scholarly journals Modelling of elastic-plastic behavior of cables

2018 ◽  
Vol 174 ◽  
pp. 03001
Author(s):  
Oleksandr Shimanovsky
Keyword(s):  
Cross Section ◽  
Material Behavior ◽  
Structural Systems ◽  
Plastic Behavior ◽  
Rigid Plastic ◽  
Limit Values ◽  
Plastic Deformations ◽  
Linear Hardening ◽  
Elastic Plastic ◽  
Deflected Mode

The paper describes general calculation theory and elasticplastic behavior of cables - bearing elements of suspension structural systems. It is mentioned that this theory is based almost on the same assumptions as the theory of cable calculation at behavior of material in elastic range, excluding additional supposition in the part of idealization of real dependence between stresses and deformations on account of difficulties with using the latter in actual structures design. For that reason, this dependence is replaced with a model in the form of analytic curve or, as it is accepted to say in this case, a diagram, which is built according to some simple mathematic rule, reflecting element behavior conditions and characteristics of its material. It is stated that four main models of material behavior are used in practice: elastic-plastic, elastic-plastic with linear hardening, rigid-plastic and rigid-plastic with linear hardening. Conditions of occurrence of plastic deformations in all behavior stages of cable cross section are determined. Interrelations for geometrically and physically nonlinear task of the cable at active loading are provided. Methods are given and limit values of loads acting on the cable are determined. Equations defining parameters of cable deflected mode in all deformation phases and conditions of changing phases of cable behavior are given.

Stress Analysis of SS316L Tube Die Expansion for High Pressure Gas Coolers

2020 ◽  
Author(s):  
Zijian Zhao ◽  
Abdel-Hakim Bouzid
Keyword(s):  
Residual Stress ◽  
High Pressure ◽  
Plastic Material ◽  
Research Work ◽  
Material Behavior ◽  
Isotropic Hardening ◽  
Plastic Behavior ◽  
Expansion Process ◽  
Elastic Plastic ◽  
Stress States

Abstract SS316L finned tubes are becoming very popular in high-pressure gas exchangers and particularly in CO2 cooler applications. Due to the high-pressure requirement during operation, these tubes require an accurate residual stress evaluation during the expansion process. Indeed, die expansion of SS tubes creates not only high stresses when combined with operation stresses but also micro-cracks during expansion when the expansion process is not very well controlled. This research work aims at studying the elastic-plastic behavior and estimating the residual stress states by modeling the die expansion process. The stresses and deformations of the joint are analyzed numerically using the finite element method. The expansion and contraction process is modeled considering elastic-plastic material behavior for different die sizes. The maximum longitudinal, tangential and contact stresses are evaluated to verify the critical stress state of the joint during the expansion process. The importance of the material behavior in evaluating the residual stresses using kinematic and isotropic hardening is addressed.

scholarly journals Plastic deformations in the ring spherical shells

2018 ◽  
Vol 251 ◽  
pp. 04060
Author(s):  
Avgustina Astakhova
Keyword(s):  
Differential Equations ◽  
Numerical Solution ◽  
Thin Shells ◽  
Stress Dependence ◽  
Strain Intensity ◽  
Spherical Shells ◽  
Plastic Deformations ◽  
Linear Hardening ◽  
Elastic Plastic ◽  
Development Area

In the present work the results of the study of plastic deformations distribution in the thickness in ring spherical shells are presented. Resolving differential equations system is based on the Hirchhoff-Lave hypothesis, linear thin shells theory and small elastic-plastic deformations theory. The studying of the development area of plastic deformations in shells thickness are performed with using the results of the elastic solutions method. The basic relations of elastic solutions method that allow to determine the distribution areas of plastic deformations in shells thickness and along the generatrix are presented. The diagram of intense stress dependence from the strain intensity with linear hardening is received. The numerical solution is performed by orthogonal run method. Long and short spherical shells under the operation of three evenly distributed ring loads are observed. The shells have a tough jamming along the contour at the bottom and at the top. Dependency between tension intensity and deformations intensity is accepted for the case of a material linear hardening. Area of plastic deformations in shells thickness for three kinds of ring spherical shells are shown. The results for the loads differed by the value in twice are presented.

Large Elastic-Plastic Deformation Analysis of Rectangular Plates

2002 ◽  
Author(s):  
Reza Naghdabadi ◽  
Mohsen Shahi
Keyword(s):  
Lateral Displacement ◽  
Deformation Analysis ◽  
Plastic Behavior ◽  
Rectangular Plates ◽  
Computationally Efficient ◽  
Plastic Deformations ◽  
Elastic Plastic ◽  
Various Boundary Conditions ◽  
Method Of Solution ◽  
Suitable Combination

The purpose of this paper is to find a fast and simple solution for the large deformation of rectangular plates considering elastic-plastic behavior. This analysis contains material and geometric nonlinearities. For geometric nonlinearity the concept of load analogy is used. In this method the effect of nonlinear terms of lateral displacement is considered as suitable combination of additional fictitious lateral load, edge moment and in-plane forces acting on the plate. Variable Material Property (V.M.P.) method has been used for analysis of material nonlinearity. In this method, the basic relations maintain the form of stress-strain elastic formula, while material properties are modified to take into account the path-dependency involved in elastic-plastic deformations. Therefore, the solution of a von-Karman plate enduring large elastic-plastic deformations is reduced to that of an equivalent elastic plate undergoing small deformations. The method of solution employed in this study is computationally efficient and can easily be used for various boundary conditions and loadings.

scholarly journals PLASTIC DEFORMATIONS OF STEEL FRAME: STATICS AND DYNAMICS

2010 ◽  
Vol 2 (3) ◽  
pp. 101-105 ◽  
Author(s):  
Vytautas Kargaudas ◽  
Nerijus Adamukaitis
Keyword(s):  
Dynamic Analysis ◽  
Cross Section ◽  
Axial Force ◽  
Bending Moment ◽  
Transverse Force ◽  
Steel Frame ◽  
Plastic State ◽  
Strain Diagram ◽  
Plastic Deformations ◽  
Elastic Plastic

When all deformations of a column are elastic, transverse deflections of the column depend on transverse force and axial displacements depend on axial force only. These classical dependences are unsuitable for elastic-plastic deformations. Plastic deformations develop in columns when steel frame is influenced by extreme action. When a steel column is in the elastic-plastic state, the distribution of elastic and plastic deformations in the cross-section depends on both the bending moment and compressing force. The ideal elastic-plastic material is assumed in this investigation (Prandtl stress – strain diagram). If the shape of the column section is double tee, flange width is neglected with respect to web height, but the area of the flange cross-section is assumed a constant. Single-sided or double-sided yield depends on the moment and force, and therefore curvature and the axial strain of the column can be calculated when yielding dependences are determined. Transverse and axial displacements of the highest point of the column are deduced by integration and depend on two arguments: bending force and axial force. These dependences are essentially non-linear, so linear approximations can be assessed for some vicinity of axial force and bending moment values. When axial force is a constant and transverse force increases, both axial and transverse displacements tend to increase. If transverse force is a constant and axial force increases, both displacements increases but dependence lines remain different and depend on cross-section shape parameter equal to the ratio of the flange area and the area of the whole cross-section. A distinguished feature of plastic deformations is dependence on the history of loading a frame of which can be selected in an arbitrary way by an investigator if a quasi-static solution is under examination. The loading of a frame and inertia forces have to be deduced if dynamic analysis is studied. Not only the ultimate result but also the way of approaching a plastic piston – plastic hinge is important. The bended and compressed column is the structure when inelastic dynamic analysis is really important.

An Analytical Solution for Three-Dimensional Elliptical Elastic-Plastic Rolling Contact

2014 ◽  
Vol 658 ◽  
pp. 207-212
Author(s):  
Gabriel Popescu
Keyword(s):  
Residual Stresses ◽  
Yield Criterion ◽  
Tangential Force ◽  
Rolling Direction ◽  
Three Dimensional ◽  
Rolling Contact ◽  
Material Behavior ◽  
Hertzian Contact ◽  
Plastic Behavior ◽  
Elastic Plastic

An analytical three-dimensional elastic-plastic over-rolling solution is used to evaluate the plastic strains and residual stresses. Central to this plastic contact formulation is the incremental approach to deal with non-linear material behavior. The Prandtl-Reuss constitutive equations in conjunction with Huber-Mises-Hencky yield criterion and Ramberg-Osgood strain-hardening relationships are applied to describe the plastic behavior of common hardened bearing steel. The model was extended to include the tangential force in the rolling direction, assumed to be proportional to the hertzian contact pressure. Comparisons of three-dimensional pure rolling and rolling/sliding contact results were provided to elucidate the differences in residual stresses and residual profiles in case of kinematic and work-hardening materials.

scholarly journals Stretching of a cylindrical rod of variable cross-section in the theory of small elastic-plastic

2020 ◽  
pp. 78-81
Author(s):  
Николай Ильич Петров
Keyword(s):  
Cross Section ◽  
Axisymmetric Problem ◽  
Variable Cross Section ◽  
Variable Cross ◽  
Initial State ◽  
Plastic Deformations ◽  
Linearized Equations ◽  
Elastic Plastic

В работе рассматривается растяжение бесконечно длинного цилиндрического стержня переменного сечения. Используются результаты решения линеаризированных уравнений теории малых упругопластических деформаций [1-7] в случае осесимметричной задачи. Предполагается, что в начальном состоянии имеет место простое растяжение. We considers the stretching of an infinitely long cylindrical rod of variable cross-section. The results of solving the linearized equations of the theory of small elastic-plastic deformations [1-7] in the case of an axisymmetric problem are used. It is assumed that a simple stretch occurs in the initial state.

Impact With Finite Acceleration Time of Elastic and Elastic-Plastic Beams

1956 ◽  
Vol 23 (3) ◽  
pp. 411-415
Author(s):  
R. C. Alverson
Keyword(s):  
Plastic Deformation ◽  
Cross Section ◽  
Plastic Hinge ◽  
Small Time ◽  
Steel Beams ◽  
Time Interval ◽  
Transverse Impact ◽  
Rigid Plastic ◽  
Elastic Plastic ◽  
Small Time Interval

Abstract The purpose of the work described in this paper was to provide information on the elastic and plastic deformation of steel beams subjected to transverse impact. The particular impact problem treated was chosen to correspond to conditions in tests in which a beam initially at rest is struck by a massive hammer, so that a specified change of velocity is imposed at a certain cross section in a small time interval. In the present analysis the initial elastic and subsequent elastic-plastic motions were obtained by methods similar to those used by Bleich and Salvadori (3). As in (3), it is assumed that plastic deformation occurs only at a single stationary plastic hinge (in this case at the struck cross section). Results obtained are compared with those of a “rigid-plastic” solution of the same problem, in which plasticity conditions are correctly taken into account but elastic vibrations are not included.

Study on the Expansion Force of TWIP Steel Expandable Tubular in Solid Expandable Tubular Technology

2019 ◽  
Vol 142 (2) ◽  
Author(s):  
Shengkun Wang ◽  
Shengjun Huang ◽  
Minglei Wang ◽  
Gang Chen
Keyword(s):  
Twip Steel ◽  
Yield Criterion ◽  
Cone Angle ◽  
Expansion Ratio ◽  
Plastic Behavior ◽  
Expansion Process ◽  
Rigid Plastic ◽  
Linear Hardening ◽  
Plastic Model ◽  
Expansion Force

Abstract This paper focuses on the expansion process of twinning-induced plasticity (TWIP) steel tubular undergoing the large circumferential plastic deformation in expandable tubular technology. The expansion process was performed by propagating a mandrel through the tubular mechanically. This paper aimed at developing the mathematical models to predict the expansion force required for the radial expansion of the TWIP steel tubular using the rigid-perfectly plastic model and the linear hardening rigid plastic model, respectively. The volume incompressible condition together with the Tresca yield criterion was used to describe the plastic behavior of the tubular material in the expansion process. Besides, the finite element analysis of the expansion process was developed using the commercial software abaqus to validate the theoretical results and determine the scope of application of the derived expansion force formula. Further to this, the effect of the process parameters, such as the expansion ratio, friction coefficient and the cone angle, on the expansion force was investigated. It was found that the expansion force difference of two models have similar variation trend. The accuracy and applicability of the expansion force formula using the linear hardening rigid plastic model improve as the expansion ratio increases and the expansion cone angle decreases.

scholarly journals Elastic-Plastic Behavior of Compacted Loess under Direct and Cyclic Tension

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Shixin He ◽  
Haibo Bai
Keyword(s):  
Mechanical Energy ◽  
Strain Curve ◽  
Material Behavior ◽  
Plastic Behavior ◽  
Phase Lag ◽  
Elastic Plastic ◽  
Cyclic Loading And Unloading ◽  
Cyclic Tension ◽  
Tension Tests ◽  
Loading And Unloading

Tensile strain is one of the main variables that affect fracturing in soil. This paper focuses on an experimental investigation of the deformation characteristics of remolded loess in direct and cyclic tension tests. The material behavior was approximated as elastic-plastic by ignoring the effect of time. In direct tests, the results showed that the change in slope of the stress-strain curve depended on the water content. The plastic constitutive relation was described by two methods. In cyclic loading and unloading tests, the remolded loess exhibited hysteresis (a phase lag), which led to dissipation of the mechanical energy. And no compaction limit phenomenon was found. A simple mathematical model was proposed to predict the plastic cyclic characteristics, and it was validated by the new test data.

Impulsive Loading of Elastic-Plastic Beams

1956 ◽  
Vol 23 (4) ◽  
pp. 515-521
Author(s):  
J. A. Seiler ◽  
B. A. Cotter ◽  
P. S. Symonds
Keyword(s):  
Cross Section ◽  
Initial Velocity ◽  
Sine Wave ◽  
Impulsive Loading ◽  
Ductile Material ◽  
Rigid Plastic ◽  
Elastic Deformations ◽  
Simply Supported ◽  
Elastic Plastic ◽  
Plastic Type

Abstract A simply supported uniform beam of ductile material, subjected to impulsive loading such that the initial velocity is a half-sine wave, is considered in this paper. The elastic and elastic-plastic motions are discussed under the assumption that plastic flow is confined to one cross section, and the final deformations are compared with those computed from an analysis which neglects all elastic deformations. The purpose of the work is to provide further information which may help in estimating the range of validity of the latter (“rigid-plastic”) type of analysis.

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