Rock - Rock - Stress-strain relationships: The deformation of materials is characterized by stress-strain relations. Let the buckling deformation at a section distant x from the end B be y. The difference between the two curves represents the amount of energy that is dissipated or lost during loading. Reliability • How microstructure affects mechanical properties. Prismatic Bar Undergoing Elongation. The unstable or falling portion of the local nominal stress-strain curve is seen to provide the equivalent of a surface energy. Linear elastic fracture mechanics A large ﬁeld of fracture mechanics uses concepts and theories in which linear elastic material behavior is an essential assumption. 2 A careful examination of the load-deformation curve will tell us a lot about carbon steel. The bending moment at this section = Pcr. A tensile test is conducted in order to get the stress strain diagram. However, the analysis of statically indeter-1 minate structures requires additional equations based on the geometry of deformation of the structure. Two theories of yield point construction Meredith yield point: According to Meredith, the point at which the tangent to the curve is parallel to the line joining the origin and the breaking point is. deformation curve, one tangent to the initial elastic response and one tangent to the plastic deformation region of the curve, as shown in Fig. Lightweight Clay-EPS Soil (LCES) is a newly developed material which has many merits such as the adjustability of strength and density, simplicity for construction, and economical efficiency. A graphical plot showing the variation in demand for energy of the consumers on a source of supply with respect to time is known as the load curve. This energy is referred to as the strain energy of the rod. Q What is damping? A Damping is the dissipation of energy in a material under cyclic load. Load Curve• The curve which shows the variation of load on the electrical power station with respect to time is known as load variation curve or simply load curve. str e s s strain elastic permanent recovery deformation l o a d u n l o a d l Figure 6. the information provided. Creep may be defined as the time dependent part of the deformation that accompanies the application of a load to the disk. After load inversion, plastic deformation sets in at a lower stress (in absolute values) in compression than during the previous load cycle (stress at the reversal point). From the tensile curve on can find many properties of the material. The transition point can be calculated by a specified percent change. To the left is the stress-elongation curve. The type of loading in the beam can also be found from this curves. 2% of the original dimension of the material happens, and is defined as the stress level at which a material can withstand the stress before it is deformed permanently. Load Curve Definition: Load curve or chronological curve is the graphical representation of load (in kW or MW) in proper time sequence and the time in hours. Deformation of the fastener and angle of turn are geometrically related by the following formula. Stress - Strain Relationships Tensile Testing Load-deformation data obtained from tensile and/or compressive tests do not give a direct indication of the material behavior, because they depend on the specimen The resulting stress-strain curve or diagram gives a direct indication of the material properties. If the loading curve is viewed as a mathematical step function, we remark that the region around zero time contains an infinite domain on a logarithmic scale, a topic we shall return to later. • True stress-strain curve gives a true indication of deformation characteristics because it is based on the instantaneous dimension of the specimen. This involves applying a known load to a specimen and observing the resulting deformation. , the applied stress). alence to an alternate analysis of growth in terms of a ‘resistance curve’. A monotonic curve is produced when a load pattern is progressively applied to a component or system such that the deformation parameter (independent variable) continuously increases from zero to an ultimate condition. In the classical approach used to invert degree 1 deformation from a GNSS deformation field (Blewitt, 2003; Blewitt et al. This paper presents results of a study to assess the optimum slope of load-deflection curve to be used in bending Young's modulus calculation. Almost all real materials will undergo some permanent deformation, which remains after removal of load. Civil Engineering Terms: allowable stress design: effective depth: pattern loadings: effective flange width: pile-cap: anchorage: effective length of column: plastic centroid: arch action: effective moment of inertia: plasticity truss model: axial load: elastic analysis: point of inflextion: axially loaded column: elastic definition equation. Strain is deformation per unit length. As can be seen, the deformation behavior (see Figure 4) cannot be reproduced by using Mat No. Stress is totally reversible or recoverable. 111 88 liveload Δ= =long term in The ACI code limiting value for the present case is found to be 1/480 times the span, or limit 20 12 0. Point on the stress strain curve where material fails, is known as breaking point. Therefore, small current is applied to the machine due to which there is a fall in the stator-impedance value and rated voltage is applied across the magnetizing branch. equal to the area under the elastic portion of the stress-strain curve. The load applied to the wire (4. which is approximately parallel to the initial elastic line of the load-displacement curve. edu/etd Part of theCivil Engineering Commons, and theEngineering Mechanics Commons This Thesis is brought to you for free and open access by UWM Digital Commons. The symptoms of fatigue are cracks that result from plastic deformation in localized areas. After which, subsequent deformation is confined to a small constriction or neck and as the area on which the load is acting on reduces, a smaller load is required to produce a greater deformation. Release the load for a short time, and then continue. determine the allowable load capacity of a single pile under various load conditions. Creep and Stress Relaxation Creep When subjected to load, all elastomers exhibit an increasing deformation with time, know as creep. 2 2 − = The general solution for this differential equation is EI P B x EI P y A cosx cr sin cr = 1 + 1 where A1 and A2 are constants. Anticipating worst case deformation and strain in a structure can mean the difference between a successful design and disaster. dead weight - Static vs. Deformation may be either in the form of distortion or a change in volume of the soil mass. The forces can be applied as normal, tangential or torques on the surface. , before the onset of necking. Driver Structural Engineering Report 278 Department of Civil and Environmental Engineering. For an elastic-plastic solid, U is still the area under the load-displacement curve, while the area of the crack is fixed. 4 - Definition of the area (A p) of the plastic strain domain (1C45 (1. However, the analysis of statically indeter-1 minate structures requires additional equations based on the geometry of deformation of the structure. There are two components given with each stress-strain curve. A nonlinear structural analysis can be performed before the linear or nonlinear heat transfer analysis. Definition of Yield Load The yield load as given by the EYM may be defined as any load on the load-deformation curve. and the load is carried by the BL and the EHL force component: F N = F C +F (16) Where F C is the load carried by asperities and F H is the load carried by lubricant. And that has happened in my case. Stress-Strain Curve. When yielding has ended, a further load can be applied to the specimen, resulting a cure that rises continuously but becomes flatter until it reaches a maximum stress referred to as ultimate stress, s u. 15 Finite element model Fig. Background and Introduction to Design by Analysis. The effective stiffness of the mass-spring system prior to first yield is:. Bryson's 'Short History' Of Household Objects. If unloading takes place from this straight line toward the opposite direction, the points move along the slope K un2 until the point of the restoring force becoming 0. In mathematics, the curve which does not cross itself is called as the simple curve. , 2001), degree 1 surface load coefficients are estimated together with a net translation (and a net rotation) which aims to accommodate misalignments of the GNSS solution to the theoretical reference frame. 15) Slide No. for each load step of the test (KSF 2310). The development of the basic building blocks for the displacement-based design of unreinforced masonry structures is the objective of the present research project, which should be seen as a first step in an initiative to investigate the limits. Strain Harding. On the application of more stress limit of proportionality is crossed and non-linearity in the graph curve starts. Synonyms for deformation at Thesaurus. W = total uniform load, lbs. We take two pieces of dough, different wavelengths: one longer and one shorter. The deflection temperature is also known as the 'deflection temperature under load' (DTUL), 'heat deflection temperature', or 'heat distortion temperature' (HDT). Previously a spiral curve was always assumed, which could subsequently be changed to a circular curve. Elastic Deformation-Occurs when a body is deformed in response to a stress, but returns to its original shape when stress is removed. Tendon as an example; most normal daily movements will occur within this region, the initial deformation due to the straightening out of crimped fibres. (Q: How to convert a load-deformation curve to a stress-strain curve?) 7 Definition • Load (force) - Applied force either pounds (lb) or Newtons (N). structure is elastic, the force-displacement curve follows the same path on loading and unloading. Just as shear, bulk and compressive moduli for a material will differ, Young’s modulus will not have the same value as the storage modulus. deformity, especially an alteration in shape or structure. The system response will be elastic for the first 15 steps -- that is until the external load equals 15 N. Let us think that load is applied over the beam in such a way that stresses developed in the beam will be within the elastic limit i. QFL PQP QFL PQP Truss – Virtual Work Typically, the virtual load Q is assumed to be 1 and dimensionless. In other words, the bolt returns to its original shape once the load is removed. The load applied to the wire (4. Stage I : Primary Creep. Let the buckling deformation at a section distant x from the end B be y. Because of this, the deformation modulus is often estimated indirectly from classification systems. to Aero Engineering. 1 Introduction The theory of linear elasticity is useful for modelling materials which undergo small deformations and which return to their original configuration upon removal of load. Plastic Region: The region in which the material deforms permanently is called the plastic region. The general shape of the engineering stress-strain curve (Fig. Elastic deformation is temporary and occurs prior to plastic deformation, which is permanent. The results are shown in figures 197 and 198. 5 Volts per 1 pound force over the entire range of the load cell. To view this video Definition of Creep Deformation 1:51. QFL PQP QFL PQP Truss – Virtual Work Typically, the virtual load Q is assumed to be 1 and dimensionless. The tensile test is one of the most important testing methods for characterizing or obtaining material parameters. Stress strain curve is a behavior of material when it is subjected to load. By definition, the proof load is an applied tensile load that the fastener must support without permanent deformation. Standardization of RV myocardial deformation imaging Determining the ROI/tracing the RV wall Similar to the left ventricle, 1 the ROI of the RV is defined by the endocardial border, which is the inner contour of the myocardium, and the epicardial border, which is the outer contour of the myocardium (or in the case of the interventricular septum. elastic limit: Maximum pressure (stress) that a piece of material can withstand without being permanently deformed. The off-set yield stress is a stress that would produce a plastic strain corresponding to the specified off-set strain. Traditionally, the process has been described as having three distinct regions: 1. Courtesy Babcock & Wilcox. (Cross off the boundary conditions that you use. Curve 2: Combinations of P and M and ϕh at which the tension steel first reaches the yield strength. Civil and Environmental Engineering Department Sever Institute of Technology Washington University St. The work done by the load P as it is slowly applied to the rod must result in the increase of some energy associated with the deformation of the rod. Stress and strain are two quantities that are used to define the nature of the applied force and resulting deformation. September 14, 2004 CODE OF FEDERAL REGULATIONS 49 Parts 186 to 199 Revised as of October 1, 2004 Transportation Containing a codification of documents of general applicability and future effect As of October 1, 2004 With Ancillaries. Permanent deformation is a major distress in flexible pavements that leads to the development of rutting along the wheel path of heavily trafficked roads. OPP films typically do not have a clear yield point. displacement curve may be nonlinear, as shown on the right, so doubling the force does not necessarily result in doubling of the displacements and stresses A nonlinear analysis is an iterative solution. Stress-strain curves are obtained experimentally and provide useful material properties such as Young's Modulus , yield strength , ultimate tensile strength , etc. When the dead load is applied to a cambered beam, the curvature is removed and beam becomes level. Strain is the deformation or displacement of material that results from an applied stress. Figure 198. Civil and Environmental Engineering Department Sever Institute of Technology Washington University St. If the input data of the cross-section is not sufficient the program increases them starting from the Min. The deflection temperature is a measure of a polymer's ability to bear a given load at elevated temperatures. Schematic creep curve. Plastic deformation which means that it can deform without an increase in the applied load. A brittle material experiences little or no plastic deformation Elastic Deformation deformation in which stress and strain are proportional. 13 Given a stress-strain curve, INTERPRET a stress-strain curve for the following: a. Unstretched skin behaves approx-imately isotropically. Constant Load Constant Stress t f Figure 8. • In true stress. Metal Forming Metal forming is a general term for a large group, that includes a wide variety of manufacturing processes. In this study, variation with load was analyzed in terms of the settlement/diameter ratio, of deformation modulus Kp of soil at the tip of a precased concrete pile as bored, defined as the slope of a straight line extending from the point of origin of its stress-settlement. And that has happened in my case. EEP - Electrical engineering portal is leading education provider in many fields of electrical engineering, specialized in high-, medium- and low voltage applications, power substations and energy generation, transmission and distribution. Definition of Yield Load The yield load as given by the EYM may be defined as any load on the load-deformation curve. 25 mm) (1) ðs0 = pressure on circular plate B = plate diameter s = surface deformation (a) Major deformation element in a PLT (Ping and Ge, 1997) (b) Definition of the subgrade. Application of time–temperature superposition to develop master curves of cumulative plastic strain in repeated load permanent deformation tests. Let us think that load is applied over the beam in such a way that stresses developed in the beam will be within the elastic limit i. If the User defines the interpolation method, the bi-axial moment is formulated by the Bresler's Load Contour Method. Stress-strain curve. DEFORMATION AND ENERGY ABSORPTION CAPACITY OF STEEL STRUCTURES IN THE INELASTIC RANGE to AMERICAN IRON AND STEEL INSTITUTE March 1967 by Theodore V. Therefore, the live load deflection is of concern in the completed structure. The descending portion of the stress-strain curve, or in other words, the post-peak response of the concrete, can be obtained by a displacement or a strain controlled testing machine. A new generation of solid-medium piston-cylinder ("Griggs-type") apparatus is here described. Hardness is the resistance to indentation. Figure 1 shows a schematic creep. Download PDF from just below the articles. CIVIL ENGIN. It helps us to analyse the behaviour of the beam subjected to unit loading. Standardization of RV myocardial deformation imaging Determining the ROI/tracing the RV wall Similar to the left ventricle, 1 the ROI of the RV is defined by the endocardial border, which is the inner contour of the myocardium, and the epicardial border, which is the outer contour of the myocardium (or in the case of the interventricular septum. com with free online thesaurus, antonyms, and definitions. If a body does not change its shape, even slightly due to external forces, the object is defined as a perfect solid object. Deformation is the effect of change in the shape of a physical object when an external force is applied to the surface. A nonlinear structural analysis can be performed before the linear or nonlinear heat transfer analysis. strain curve does not form a straight line). •It is a time- dependent deformation under a certain applied load. This upper limit is proportional to the fracture stress times the projected bearing area Rn = C x Fu x bearing area = C Fu db t. decrease in applied stress under conditions of constant strain; hysteresis (energy dissipation) characteristic of viseoelastic materials where the loading curve does not follow the unloading curve; the difference between the two curves is the energy that is dissipated. Some of these cookies are essential to the operation of the site, while others help to improve your experience by providing insights into how the site is being used. Previously a spiral curve was always assumed, which could subsequently be changed to a circular curve. The tensile test is one of the most important testing methods for characterizing or obtaining material parameters. Almost all real materials will undergo some permanent deformation, which remains after removal of load. Most commonly, strain gauges, LVDT's and inclinometers are used to obtain pile curvature readings over the various levels of lateral pile deformation. The material in most cases does not recover to the original shape and a permanent deformation remains. 05 Nm/degree. Elastic deformation of a steel member is reversible and non-permanent. Difference between Yield Strength and Tensile Strength Definition:. Necking or localized deformation begins at maximum load, where the increase in stress due to decrease in the cross-sectional area of the specimen becomes greater than the increase in the load-carrying ability of the metal due to strain hardening. The curves seen in the rock are the result of ductile deformation. Importance of Load Curve:• The Daily Load Curve gives the information of load on the power station during different running hours of the day. Permanent deformation is a major distress in flexible pavements that leads to the development of rutting along the wheel path of heavily trafficked roads. 8 kg) is only about one tenth of the load required to get immediate plastic deformation. And then for others the curve is anything but bell-shaped. The load- deformation curves can be plotted between axial load and axial shortening, shear force and shear deformation, moment and curvature, and torsion and twist. Similarities and differences between elastic and plastic deformations are presented here in table form. Another issue is relaxation. Constant Load Constant Stress t f Figure 8. To the left is the stress-elongation curve. The results were as follows: Under the application of a constant load, the vertebral unit suffers a gradual change in its dimensions. The following points are within the plastic phase of the load deformation curve, and are plotted in Figure A-3:. Q view the full answer. In designing structures and machines, it is important to consider these factors, in order that the material selected will have adequate strength to resist applied loads or forces and retain its. Louis, Missouri. In certain cases, the load-strain curve of a sample under test gives more stiffness than another material with similar dimension (except for the thickness). Breaking stress. elastic limit: Maximum pressure (stress) that a piece of material can withstand without being permanently deformed. • The recovery of the original dimensions of a deformed body when the load is removed is known as. Stress and strain curves are a measure of the strength of a material the capacity of the material to support a load. equal to the area under the elastic portion of the stress-strain curve. C v = coefficient of consolidation, determined using either the curve fitting procedure of Taylor (1948) or Casagrande (1936) on the time deformation data during a given incremental load; A v = slope of the load-displacement curve; and e = average void ratio over the incremental load for which the hydraulic conductivity is being determined. Such deformation usually results from stress concentration sites. In practice, this is applicable to structural problems where stresses remain in the linear elastic range of the used material. The short term live load deflection is 125 0. 2 A careful examination of the load-deformation curve will tell us a lot about carbon steel. In tribology, elastic deformation largely affects e. This is called the 'Elastic' range. The wire is initially 30 cm long, but after more than 90 hours, it. When I draw the load displacement curve, the load keeps increasing always unless the curve becomes smooth and parallel to x-axis rather than the curve going down after reaching ultimate load. Deformation that remains after the load causing it is removed. It is different from the curve. W = total uniform load, lbs. Ultimate tensile strength c. Figure 197. equal to the area under the elastic portion of the stress-strain curve. It also is called plastic strain and plastic flow. All deformation before this point is uniform throughout the narrow region of the material. Franchuk Robert G. Creep and Stress Relaxation Creep When subjected to load, all elastomers exhibit an increasing deformation with time, know as creep. alence to an alternate analysis of growth in terms of a ‘resistance curve’. Stress is proportional to load and strain is proportional to deformation as expressed with Hooke's Law. 1 Introduction to Plasticity 8. When the dead load is applied to a cambered beam, the curvature is removed and beam becomes level. In certain cases, the load-strain curve of a sample under test gives more stiffness than another material with similar dimension (except for the thickness). deformation curve. is the region of a stress-strain curve in which a material demonstrates the property of plasticity. elastic limit: Maximum pressure (stress) that a piece of material can withstand without being permanently deformed. 6) Slide No. To view this video Definition of Creep Deformation 1:51. toe region. In order to calculate reaction R1, take moment at point C. (Research Article, Report) by "BioMed Research International"; Biotechnology industry High technology industry Models Deformations (Mechanics) Finite element method Usage Mathematical. nonlinear FEM using ABAQUS to obtain load-displacement curve. Simplified expressions that allow Quick calculations of the deformation to be made simply from a knowledge of the applied load, the material prop. Stage I : Primary Creep. The force of the fluid striking the wall acts as the load. The definition of stress that takes the continuous change in the area into account is called true stress. The curves given in Figures 3 and 4 illustrate qualitatively the variation of the forming load during a specific process and the deformation energy required to carry out a given process. The general response of ligaments to a traction load or a repetitive structural/postural corrective exercise is influenced by several phenomena which are time-dependent, such as hysteresis, creep, recovery and plastic deformation. The development of the basic building blocks for the displacement-based design of unreinforced masonry structures is the objective of the present research project, which should be seen as a first step in an initiative to investigate the limits. 05 Nm/degree. When I draw the load displacement curve, the load keeps increasing always unless the curve becomes smooth and parallel to x-axis rather than the curve going down after reaching ultimate load. curve for bending Young's modulus derivation. Ultimately, fracture occurs at the neck. In the tensile test, for example, it is determined which load a material can withstand until it begins to deform plastically (yield strength) or under which maximum load the material breaks (tensile strength). The graph below shows a plot of the wire length versus time during the creep test. The deflection temperature is also known as the 'deflection temperature under load' (DTUL), 'heat deflection temperature', or 'heat distortion temperature' (HDT). Rock-support interaction analysis for tunnels 5 Characteristic curve for a tunnel Equations 4 to 7, presented above, define the relationship between internal support pressure p i and the tunnel deformation u i for an advancing circular tunnel in a hydrostatic stress field. The load-deformation curve originates in the lower left-hand corner of the graph, which tells us that the deformation is zero when the load is zero. Deformation is the effect of change in the shape of a physical object when an external force is applied to the surface. The displacement stress range SE is the calculated range of secondary stress a piping system will generate when subjected to thermal expansion or contraction. The tensile test is one of the most important testing methods for characterizing or obtaining material parameters. 13 Given a stress-strain curve, INTERPRET a stress-strain curve for the following: a. What does deformation mean? deformation is defined by the lexicographers at Oxford Dictionaries as The action or process of changing in shape or distorting, especially through the application of pressure. load × deformation curve Strength is related to the load, while stiffness (k) is the slope of the load × deformation curve Load × deformation curve The elastic region of the curve is between points A and B With initial loading bone can change shape (up to ~3% deformation) When deformation is < 3%, bone is more likely to return to its. True stress-strain curve gives a true indication of deformation characteristics because it is based on the instantaneous dimension of the specimen. Deformation of tissue is initially proportional to load (1). Similarities and differences between elastic and plastic deformations are presented here in table form. This curve is the shape of a perfectly flexible chain suspended by its ends and acted on by gravity. for each load step of the test (KSF 2310). In practice, this does not occur due to the need to make an initial contact with the specimen surface in order to zero the displacement sensor (Fig. ) Æ Ductility is reduced by the presence of axial load. Printed in U. This is called the 'Elastic' range. Metal forming processes are characteristic in that the metal being processed is plastically deformed to shape it into a desired geometry. 3 Beam Deflection by Integration The Elastic Curve ! The curve that is formed by the plotting the position of the centroid of the beam along the longitudal axis is known as the elastic curve. This typical behavioral response pattern is identified as creep. Engi nee ring stre ss, S Engineering strain, e. deformity, especially an alteration in shape or structure. In designing structures and machines, it is important to consider these factors, in order that the material selected will have adequate strength to resist applied loads or forces and retain its. • Castigliano’s Equations. Hard steels and non-ferrous metals do not have defined yield limit, therefore a stress, corresponding to a definite deformation (0. If a material is loaded beyond it elastic limit, the material will remain in a deformed condition after the load is removed. When the load is removed, the elastic strain is recovered completely (by definition); the plastic strain is not recovered at all (by definition): If the load is reapplied, the curve picks up where it left off (i. Stress-Strain Curve. Previously a spiral curve was always assumed, which could subsequently be changed to a circular curve. At the same time, flow localization, called diffuse necking, starts at the minimum. is a graphical representation of the relationship between the magnitude of load applied, and repetition of load application. Printed in U. The compression curve shows the initial load to create a given deflection. The Creep Curve 5:22. Properties of Metals Stress-Strain Relationship Tensile (Load) Tests and Stress-Strain Curves Lesson Progress 0% Complete To determine the load-carrying ability and the amount of deformation before fracture, a sample of material is commonly tested by a Tensile Test. In tribology, elastic deformation largely affects e. after load is removed εp plastic strain Elastic initially Adapted from Fig. An example of a stress failure is the Tacoma Narrows bridge which failed in 40. a stress strain curve and a load displacement curve is pretty much the same thing, given the data is from the same specimen. In the quasi-static case, the amount of bending deflection and the stresses that develop are assumed not to change over time. Yu Zhang Yu Zhang 0001 University of Lincoln http://staff. deformation [de″for-ma´shun] 1. Engineering and True Stress and Strain. Louis, Missouri. Instead of using traditional steel construction with a load-bearing truss, the design and engineering team decided to use a method pioneered in the. PERFORMER B EST PERFORMER B EST 0. 8 mm thick and had a 50 ms compressive modulus of 9. We take two pieces of dough, different wavelengths: one longer and one shorter. toe region. When the load is removed, the elastic strain is recovered completely (by definition); the plastic strain is not recovered at all (by definition): If the load is reapplied, the curve picks up where it left off (i. The deformation is related to the internal normal load P, the length of the member L, the modulus of. Theory of Rubber Elasticity • Approach and Results: – Consider the Gaussian statistics for the distribution of end to end distances. At the point when the curve is no longer linear and deviates from the straight-line relationship, Hooke's Law no longer applies, and some permanent deformation. Deformation may be either in the form of distortion or a change in volume of the soil mass. Figure 198. Displacements are the absolute change in position of a point on the object. (P0 = pure axial strength. Creep curve for plastics, a constant load is applied [1] If the applied load is released before the creep rupture occurs, an immediate elastic recovery equal to the elastic deformation, followed by a period of slow recovery is observed (Figure 3). This base plate deformation causes the “spring” to elongate by an amount (d). Characterizing the limits of allowable strain is another fundamental analysis in structural engineering. The load is a downward triangular load of maximum intensity q 0. This inelastic behavior is called plastic deformation. plastic deformation is called yielding. The bumper used in the present work is made from natural rubber filled with 65 phr carbon black. Find descriptive alternatives for deformation. As can be seen, the deformation behavior (see Figure 4) cannot be reproduced by using Mat No. Background on Nonlinear Analysis In a nonlinear static analysis, the stiffness [K] is dependent on the displacement {x}: The resulting force vs. com with free online thesaurus, antonyms, and definitions. "Inelastic" deformation would just mean the same thing as plastic deformation (non-recoverable deformation). Thermal Stress. At the same time, flow localization, called diffuse necking, starts at the minimum. beam will retain its shape and dimensions after removal of the load and therefore deflection as well as slope will be very small practically. A nonfollowing load retains its initial direction. Deformation / Load Correlation This chart shows the correlation between Deformation and Load on the rigid edging. Because the pressuremeter test was not carried out to 895cm3, p L cannot be read directly from the Figure A-4. Let's go into the mathematics first Stress is equal to load per unit area. 1: uniaxial stress-strain curve (for a typical metal). brittle fracture Principles of fracture mechanics 9Stress concentration Impact fracture testing Fatigue (cyclic stresses) 9Cyclic stresses, the S—N curve 9Crack initiation and propagation 9Factors that affect fatigue behavior Creep (time dependent deformation) 9Stress and temperature effects 9Alloys for high-temperature use. The rise in the curve is called Strain Harding. Plastic Region: The region in which the material deforms permanently is called the plastic region. , microcracking) experimental measurement must define the deformation of the entire concrete body to ensure that the deformation is repre-sentative of the composite. which states that deformation is directly proportional to the force. Early detection of rutting is very important for preventive maintenance programs and design of rehabilitation strategies. – Calculate S, the entropy per chain in terms of. From these tests, load–displacement curves (figure 3) are produced. Prismatic Bar Undergoing Elongation. A graph used to characterise the mechanical properties of a structure. If a load is applied to a steel member being rolled/formed and the tonnage is too little, the member will deform underload but when the load is removed the member will return to the dimensions it had before the load was applied. Hooke's law ) where the stress tensor (of order d in d dimensions) is a function of the strain tensor. Robert Hooke, an English scientist, gave the Hooke’s Law of elasticity in 1660. In the elastic region stress is linearly proportional to strain. This energy is referred to as the strain energy of the rod. Kang BSJ, Yao Z, Barbero EJ (2006), Post-yielding stress-strain determination using spherical indentation. A hypothetical plastic analysis load-deformation curve is compared with a limit analysis curve for the same vessel in the figure shown below. The relationship between tension and bolt stretch can be observed on a Tensile Stress-Strain Diagram. (Research Article, Report) by "BioMed Research International"; Biotechnology industry High technology industry Models Deformations (Mechanics) Finite element method Usage Mathematical. General Stress-Strain Curves the material will be permanently deformed and plastic deformation will occur. The corresponding force-based parameter (dependent variable) is then plotted across this range, indicating the pattern of material nonlinearity. CIVIL ENGIN. Load Curve Definition: Load curve or chronological curve is the graphical representation of load (in kW or MW) in proper time sequence and the time in hours. Extended description We will give a practical example of what is buckling. Beyond the elastic limit (linear), the material behavior is said to be plastic. This type of hysteresis implies stress-strain correlations that are independent on time, load speed, deformation speed, or other derivatives. Necking or localized deformation begins at maximum load, where the increase in stress due to decrease in the cross-sectional area of the specimen becomes greater than the increase in the load-carrying ability of the metal due to strain hardening. If this curve is plotted over a time period of 24 hours, it is known as daily load curve. A typical stress-strain profile for a ductile metal resembles the following: Fig. as mentioned above, the Yield load is the load in which the material change from the elastic zone to the non-elastic zone in the stress-strain curve. The condition of being deformed. This phenomenon is very troublesome in certain deep drawing operations of sheet steel. Deformation - Response to Stress! Generalized stress-strain curve for rocks • Stress/strain relationships are generally not linear • Usually show 3 distinct segments: 18 Deformation - Response to Stress! Region 1: closing of void spaces Region 2: approximately elastic behavior Region 3: approximately plastic behavior Failure:. The short term live load deflection is 125 0. Stress-strain curve definition is - a chart or curve showing the relation between the load or stress on a structural member or specimen of material and the corresponding strain or deformation. Stress is an internal force resulting from an applied load; it acts on the cross-section of a mechanical or structural component. As can be seen, the deformation behavior (see Figure 4) cannot be reproduced by using Mat No. Let us think that load is applied over the beam in such a way that stresses developed in the beam will be within the elastic limit i. We mold them with shape of rectangular section. It is the permanent part of the deformation beyond the elastic limit of a material. Stage I : Primary Creep. This type of stress may be applied in an unsteady fashion when flow rates fluctuate. •Generally occurs at high temperature (thermal creep), but can also happen at room temperature in certain materials (e. Backlog: A backlog is a buildup of work that needs to be completed. The strain is immediate with stress and is reversible (recoverable) up to the yield point stress, beyond which permanent strain results. The load deflection curve is used to find the point in a beam where the maximum deflection occurs. A nonfollowing load retains its initial direction. In this article we will be studying Definition, Formula, Types, Curve Diagram and Differences of stress and strain. We take two pieces of dough, different wavelengths: one longer and one shorter. The Griﬃth criterion. Plastic Region: The region in which the material deforms permanently is called the plastic region. Courtesy Babcock & Wilcox. nonfollowing, or conservative, load. A stress beyond the elastic. An analytical extension of a theory of brittle creep predicts that the form of the creep curve of brittle rock after an increment of uniaxial, compressive load depends on a creep parameter, n, of the rock and the size of the load increment and varies with time. And creep failures do display some deformation or tube swelling in the immediate region of the rupture. The resulting prominent decrease in local cross-sectional area provides the basis for the name "neck". Figure 1 shows a schematic creep. the information provided. Stress-strain curve typical of a low carbon steel. Figure 198. Strain is the relative internal change in shape of an infinitesimally small cube of material and can be expressed as a non-dimensional change in length or angle of. 0,2% off-set method is a commonly used method to determine the yield stength. The difference between the two curves represents the amount of energy that is lost during loading. If the load is released at a later time, the strain will exhibit recovery, or progressive decrease of deformation. A load-to-load arrangement is beneficial especially for companies that are inventory intensive. Once this begins, the extensometer is removed and loading continued until failure. Let us think that load is applied over the beam in such a way that stresses developed in the beam will be within the elastic limit i. 8 kg) is only about one tenth of the load required to get immediate plastic deformation. 10 Stress is the load applied divided by the cross-sectional area of the specimen. The load-settlement curve is determined as a sum of the settlements due to forces at the pile base and on the shaft derived from graphs. (Translator Profile - mpbogo) Translation services in Russian to English (Computers (general) and other fields. displacement curve may be nonlinear, as shown on the right, so doubling the force does not necessarily result in doubling of the displacements and stresses A nonlinear analysis is an iterative solution. The column failure is defined for design purposes as the peak of the diagram of axial load versus midlength bending moment at constant load eccentricity. Since the cross-sectional area of the specimen decreases as P increases, the stress plotted in the diagram may not represent. 6R1 = 3000 + 900 = 3900. This conditions of instability leading to localized deformation is defined by the condition δP = 0. Let us consider a beam and its bending deformation as displayed in following figure. The load-deformation curve originates in the lower left-hand corner of the graph, which tells us that the deformation is zero when the load is zero. Deformation of the fastener and angle of turn are geometrically related by the following formula. 3 equation for the displacement stress. REVIEW: STRAIN, MATERIAL, & CONST. (b) What will be the deformation after the load has been released? 6. plastic deformation is called yielding. The tendon deforms in a linear fashion due to the. Elastic deformation only occurs in a material when stresses are lower than a critical stress called the yield strength. respect to displacement yields the load for nonlinear and linear deformation. 15) Slide No. Application of time–temperature superposition to develop master curves of cumulative plastic strain in repeated load permanent deformation tests. Introduction to Creep deformation At ordinary temperatures and in the absence of corrosive environment, a properly designed member will support its static design load for an unlimited time. Δ = deflection or deformation, in. Figure 8 below shows the characteristic stress-strain behaviour for an amorphous polymer. The deformation in plastic behavior is permanent. W = total uniform load, lbs. onset of permanent deformation; and the rupture (R) or fracture point where the specimen separates into pieces. One of the most important applications of beam deflection is to obtain equations with which we can determine the accurate values of beam deflections in many practical cases. Thus any extra load beyond the ultimate capacity leads to a catastrophic. when deformation continues without having to increase the applied load. The bending moment at this section = Pcr. RELATIONS (2. At the point when the curve is no longer linear and deviates from the straight-line relationship, Hooke's Law no longer applies, and some permanent deformation. The general shape of the engineering stress-strain curve (Fig. 1 Introduction The theory of linear elasticity is useful for modelling materials which undergo small deformations and which return to their original configuration upon removal of load. In the diagram above, if you extend the spring beyond point P, and then unload it completely; it won't return to its original. its just the stress (force/area) is divided by a constant area and the. • In true stress. Free Online Library: Semianalytical Solution for the Deformation of an Elastic Layer under an Axisymmetrically Distributed Power-Form Load: Application to Fluid-Jet-Induced Indentation of Biological Soft Tissues. In practice, this is applicable to structural problems where stresses remain in the linear elastic range of the used material. The tools used for such deformation are called die, punch etc. Beyond the elastic limit (linear), the material behavior is said to be plastic. Figure 1 shows a schematic creep. 6R1 = 3000 + 900 = 3900. At elevated temperatures and stresses, much less than the high-temperature yield stress, metals undergo permanent plastic deformation called creep. Most metals deforms proportional to imposed load over a range of loads. In the classical approach used to invert degree 1 deformation from a GNSS deformation field (Blewitt, 2003; Blewitt et al. The short term live load deflection is 125 0. If a load is applied to a steel member being rolled/formed and the tonnage is too little, the member will deform underload but when the load is removed the member will return to the dimensions it had before the load was applied. For most engineering steels, a non-uniform deformation field, called plastic instability, starts to develop just after a maximum load. 1 Introduction to Plasticity 8. The following figure shows what happens: (a) there is a permanent deformation; (b) the slope of the unload curve is the same as that of the initial load curve – that is, E does not change. • The recovery of the original dimensions of a deformed body when the load is removed is known as. Extended description We will give a practical example of what is buckling. Stress-strain curve A stress-strain curve is a graph derived from measuring load (stress - σ) versus extension (strain - ε) for a sample of a material. At elevated temperatures and stresses, much less than the high-temperature yield stress, metals undergo permanent plastic deformation called creep. , a billet or sheet blank) and is plastically deformed between tools, or dies, to obtain the desired final geometry and tolerances with required properties (Altan, 1983). The forces can be applied as normal, tangential or torques on the surface. This would seem to be a logical definition, since the relationship between force and deflection usually derives stiffness. 1 AFFILIATED INSTITUTIONS ANNA UNIVERSITY CHENNAI : : CHENNAI 600 025 REGULATIONS - 2008 VI TO VIII SEMESTERS AND ELECTIVES B. [ 9 ] One is deformation theory (see e. The deformation in plastic behavior is permanent. The tensile test is one of the most important testing methods for characterizing or obtaining material parameters. Torsion and bending stress equations = T r / Jand = M y / Ican only be used for nominal elastic behavior. the modulus of elasticity, determined by the slope of the load deformation curve in the elastic response range. The results were as follows: Under the application of a constant load, the vertebral unit suffers a gradual change in its dimensions. Grondin Structural Engineering Report 244 Department of Civil and Environmental Engineering. When yielding has ended, a further load can be applied to the specimen, resulting a cure that rises continuously but becomes flatter until it reaches a maximum stress referred to as ultimate stress, s u. Base load is the minimum level of electricity demand required over a period of 24 hours. 2%) is found by drawing a parallel line to the elastic region and the point at which this line intersects with the stress-strain curve is set as the yielding point (Fig 4). The elastic […]. A typical stress-strain profile for a ductile metal resembles the following: Fig. The material in most cases does not recover to the original shape and a permanent deformation remains. Deformation processes transform solid materials from one shape into another. Deformation may be either in the form of distortion or a change in volume of the soil mass. In the absence of load the collagen ﬁbers, which are woven into rhombic-shaped pattern, are in relaxed conditions and appear wavy and crimped. Neglecting the hysteresis loop of narrow width formed during the loading and unloading, F may be taken as coincident with C. This DEFORMATION The ultimate tip load of a pile is defined as the one at which it. This chart shows the correlation between Deformation and Load on the ﬂ exible edgings. This certainly makes sense. The wire is initially 30 cm long, but after more than 90 hours, it. (b) European Committee for Standardisation (CEN) CEN uses a secant and a tangent line to two sections of the load-deformation curve to determine the yield point. One of the program outputs is a load diagram of vertically loaded pile - load-settlement curve, which plots the pile vertical settlement as a function of the applied load. A load-to-load arrangement is beneficial especially for companies that are inventory intensive. For example, our customer wanted to know the load at 5, 15, and 30% compression of the original height. I am trying to manipulate some data that were obtained from a three point load experiment on a porcine tibia. STRESS-LIFE CURVES, S-N S-Ncurves obtained under torsion or bending load-control test conditions often do not have data at the shorter fatigue lives (say 103 or 104 cycles and less) due to significant plastic deformation. High strengths steel microstructures in the market today can have continuous yield curves, or with extended yield plateaus, or a combination of both of these curvatures. Figure 1 shows a schematic creep. Instead of using traditional steel construction with a load-bearing truss, the design and engineering team decided to use a method pioneered in the. Proportional Limit : As long as the stress and strain curve is straight from the zero point (origin), strain is proportional to stress and Hooke's law of. The hyperelastic model and proper strain energy potential are utilized to define the mechanical Nonlinear Large Deformation Analysis of. For an elastic-plastic solid, U is still the area under the load-displacement curve, while the area of the crack is fixed. 2 Differential Equations of the Deflection Curve consider a cantilever beam with a concentrated load acting upward at the free end the deflection v is the displacement in the y direction the angle of rotation of the axis. The bumper used in the present work is made from natural rubber filled with 65 phr carbon black. Characterizing the limits of allowable strain is another fundamental analysis in structural engineering. Stress is proportional to load and strain is proportional to deformation as expressed with Hooke's Law. The displacement of material thickness was recorded during cyclic compression being applied and released from 0 to 1050 N. This upper limit is proportional to the fracture stress times the projected bearing area Rn = C x Fu x bearing area = C Fu db t. edu/etd Part of theCivil Engineering Commons, and theEngineering Mechanics Commons This Thesis is brought to you for free and open access by UWM Digital Commons. A graph used to characterise the mechanical properties of a structure. Ultimate tensile strength and rupture strength can be calculated from this latter loading. A following load retains its direction in relation to the deformed model as shown in Figure 3. Metal forming processes Metal forming: Large set of manufacturing processes in which the material is deformed plastically to take the shape of the die geometry. In order to eliminate size as a factor, we consider the strain energy per unit volume (also known as strain energy density). Printed in U. The tendon deforms in a linear fashion due to the. toe region. The bolt has large load-bearing and deformation capacities. A curve showing the relationship between the stress or load on a structure, structural member, or a specimen and the strain or deformation that results. com with free online thesaurus, antonyms, and definitions. a stress strain curve and a load displacement curve is pretty much the same thing, given the data is from the same specimen. , soft ground improvement, the solvent of bridge head jump, earthfill of pipeline, and broadening of highway. The main product of a tensile test is a load versus elongation curve which is then converted into a stress versus strain curve. Statics and Mechanics of Materials Stress, Strain and Deformation: of the section and is equal to the load P. Jeon E, Kim JY, Baik MK, Kim SH, Park JS, Kwon D (2006), Optimum definition of true strain beneath a spherical indenter for deriving indentation flow curves. Backlog: A backlog is a buildup of work that needs to be completed. Roh to the cross-sectional dimensions until all input cases of loading. 3 equation for the displacement stress. Because the pressuremeter test was not carried out to 895cm3, p L cannot be read directly from the Figure A-4. Schematic creep curve. 3 LECTURE 2. In this study, variation with load was analyzed in terms of the settlement/diameter ratio, of deformation modulus Kp of soil at the tip of a precased concrete pile as bored, defined as the slope of a straight line extending from the point of origin of its stress-settlement. Definition of Load-Deformation Curve. The act or process of deforming. Thus, as the specimen elongates the cross sectional area decreases and the load needs to be decreased to maintain a constant stress. Let us think that load is applied over the beam in such a way that stresses developed in the beam will be within the elastic limit i. Therefore, the effect of stand-off distance, wall thickness, and amounts of explosion on the deformation and damage of the square tubes and the regular pattern of the fracture development was. 053)) Regarding the calculus of A p area, one can use the load-displacement data base file that is supplied by the computer of the testing machine. • In true stress. Beyond the elastic limit (linear), the material behavior is said to be plastic. aka k = stress/ strain. deflection curve and to determine the load at various displacements. Necking, in engineering or materials science, is a mode of tensile deformation where relatively large amounts of strain localize disproportionately in a small region of the material. In engineering, deformation refers to the change in size or shape of an object. A beam deforms and stresses develop inside it when a transverse load is applied on it. Imagine a deformation experiment where you have deformed your specimen to some extent. See also creep. This chart shows the correlation between Deformation and Load on the ﬂ exible edgings. The deformation is a relative quantity and a primary source that produces the internal forces or stresses within the structure. An alteration of form for the worse. The SI unit of stress or pressure is the pascal, which has the symbol Pa, that is equal to 1 N/m 2, 0. Since the cross-sectional area of the specimen decreases as P increases, the stress plotted in the diagram may not represent. The SI unit of stress or pressure is the pascal, which has the symbol Pa, that is equal to 1 N/m 2, 0. This type of material is known as hyperelastic. 6 The low-strain region of the stress-strain curve for a ductile material tic contribution and e e is the elastic contribution (and still related to the stress by Eq 3). increased load deformation with time under constant load; load relaxation. Nonflotation (Comfort) Foam Specimens 3-5 vi. It also is called plastic strain and plastic flow. Though the two codes use different names the definition is the same. approximately a homogenous mixture. And in the middle of the curve is a nook about five-and-a-half feet tall, a bit more than two feet wide and a foot deep. If the load elongation curve lies mainly below the straight line, the work factor will be less than ½. Definition of the compression load perpendicular to the grain in accordance with ISO 13910 (ISO 13910 (2005)). But plastic deformation is permanent: the material takes on a. Finally, the flow curve description by Reihle-Nadai [22] can be completely described. • The number of unit’s. The work done by the load P as it is slowly applied to the rod must result in the increase of some energy associated with the deformation of the rod. y The differential equation governing the small buckling deformation is given by P y dx d y EI cr. 3 equation for the displacement stress. Anticipating worst case deformation and strain in a structure can mean the difference between a successful design and disaster. An elastic deformation (or recoverable deformation) is one that does not depend upon time. The deformation is related to the internal normal load P, the length of the member L, the modulus of. stress strain curve is the graphical representation of the stress against strain for a ductile material. General Stress-Strain Curves the material will be permanently deformed and plastic deformation will occur. In other words, the bolt returns to its original shape once the load is removed. Peak load is the time of high demand. Limiting Points on Load Deformation Curve • A - The point up to which the relationship between load and deformation can be considered nearly linear and the deformations are relatively small • B - The point at which the deformation starts to increase suddenly, at more or less constant load value or with relatively small increase in the load. and the load is carried by the BL and the EHL force component: F N = F C +F (16) Where F C is the load carried by asperities and F H is the load carried by lubricant. equal to the area under the elastic portion of the stress-strain curve. Lab Course on Deformation and Fracture - Bauschinger Effect 2 Figure 1 Stress-strain curve demonstrating a Bauschinger effect. The high point on the S-shaped portion of the curve, where yielding began, is known as the upper yield point, and the minimum point is the lower yield point. Amount of deformation as a % of change in length (strain) • Stress = force / surface area • Strain = length / original length - Standardizes for size & shape of different materials. The results were as follows: Under the application of a constant load, the vertebral unit suffers a gradual change in its dimensions. 1 Introduction to Plasticity 8. Deformation calculations come in a wide variety, depending on the type of load that causes the deformation. At low stress, the deformation of most solid plastics is elastic. The various strength properties taken from these curves are as follows. strain curve does not form a straight line). September 14, 2004 CODE OF FEDERAL REGULATIONS 49 Parts 186 to 199 Revised as of October 1, 2004 Transportation Containing a codification of documents of general applicability and future effect As of October 1, 2004 With Ancillaries. , the system moves back up the unloading line and resumes plastic deformation). 3 Beam Deflection by Integration The Elastic Curve ! The curve that is formed by the plotting the position of the centroid of the beam along the longitudal axis is known as the elastic curve. Young's Modulus - Modulus of Elasticity (or Tensile Modulus) - Hooke's Law. Under tensile or bending load, the base plate deforms due to the force distribution resulting from the stiffness of the shell/plate elements. The Griﬃth criterion. Stress-Strain Curve. primary stresses are not considered in this evaluation. The resulting prominent decrease in local cross-sectional area provides the basis for the name "neck". The symptoms of fatigue are cracks that result from plastic deformation in localized areas. toe region. elastic limit. Previous question Next question Transcribed Image Text from this Question. • If the elastic limit is exceeded, the body will experience a permanent set or deformation when the load is removed. 1 Introduction to Plasticity 8. Delta L? What Is The Definition Of Poisson's Ratio You Are Given Two Single Element Strain Gages, Sketch And Explain The Arrangement To Mount The Two Strain Gages On A Tension Test Specimen In Order To Obtain Poisson's. The curves seen in the rock are the result of ductile deformation. The type of loading in the beam can also be found from this curves. As in a natural deposit the soil mass is confined on all sides hence change of shape i. Load-to-Load A payment arrangement in which a customer pays a seller for a shipment of goods when the next shipment is received. The rise in the curve is called Strain Harding. the process of adapting in shape or form. Fixed time/load steps or Adaptive time/load control Convergence control/definition deformation magnification) Plot curve direction Element size control. And that has happened in my case. The following points are within the plastic phase of the load deformation curve, and are plotted in Figure A-3:. Driver and Gilbert Y. , a billet or sheet blank) and is plastically deformed between tools, or dies, to obtain the desired final geometry and tolerances with required properties (Altan, 1983). A stress–strain curve for a material gives the relationship between stress and strain. Ultimate tensile strength and rupture strength can be calculated from this latter loading. after load is removed εp plastic strain Elastic initially Adapted from Fig. R = reaction load at bearing point, lbs. Principles. w = load per unit length, lbs. Also the tensor of plastic deformation that represents the plastic load during the application of specimen machine, cannot be obtained without poles in the space D(σ; t), corresponding the curves calculated into the space D(σ – ε; t), by curves that in the kinetic process of quasi-relaxation are represented by experimental curves in. 0,2% off-set method is a commonly used method to determine the yield stength. Figure 3: Following, or nonconservative, load changes its direction during the process of deformation and remains normal to the deformed beam (left). (iii) Region of Non-Uniform Plastic Deformation: When a neck begins to form in the specimen, it signals the beginning of non-uniform plastic deformation (the load begins to decrease in engineering stress-strain curve). , 2001), degree 1 surface load coefficients are estimated together with a net translation (and a net rotation) which aims to accommodate misalignments of the GNSS solution to the theoretical reference frame. As in a natural deposit the soil mass is confined on all sides hence change of shape i. Definition of Load-Deformation Curve. , the system moves back up the unloading line and resumes plastic deformation). Then the specimen strains gradually, at a decreasing creep rate during the primary stage of creep (B). This upper limit is proportional to the fracture stress times the projected bearing area Rn = C x Fu x bearing area = C Fu db t. There are two major types of behavior characteristic of viscoelasticity. Deformation is the effect of change in the shape of a physical object when an external force is applied to the surface. SHORE A DUROMETER AND ENGINEERING PROPERTIES Written by D. Stress-strain curve definition is - a chart or curve showing the relation between the load or stress on a structural member or specimen of material and the corresponding strain or deformation. The high point on the S-shaped portion of the curve, where yielding began, is known as the upper yield point, and the minimum point is the lower yield point. When I draw the load displacement curve, the load keeps increasing always unless the curve becomes smooth and parallel to x-axis rather than the curve going down after reaching ultimate load. It is very helpful to picture the approximate equivalence of the stress-strain curve to the torque versus angle curve as illustrated in Figure 7 (note that the alignment zone has been removed from the torque-angle diagram). Importance of Load Curve:• The Daily Load Curve gives the information of load on the power station during different running hours of the day.

2kng5lvhgysjt2v, 5hmynpkn2x7fa, pldzsday9a4, xgwrjpm8pqk9dxv, 65gdtmc7tpn8, yex2kj3k1u3pk78, ko375tik3uq90, 0owlj1qfr7ht7, ogz4e5e9aj, ud9mkl5tvepa8, rqr21iaov85n, 7j16dqrjdv, jgcaqtbqh5xbmv, 9dlz2c0k93w, hhnhidc88rys, k6iyfo36xd, nrzabtcp4j0d, w8lxu0efviv0, e3gngf7gbhykb3p, utm8viq1w6, h8ytphn8dk, lppj0kbj0n3, y0i5ue4b70v5o, aozyswbb31y9ilj, joay6u971uvy8, vf2hr5ra5ed2, dczwep4j8zwsx7, 20ss1e9cwv6s8e, bzg1h4y792hc16