Necking and fracture limit analyses of different pre-strained sheet materials in polar effective plastic strain locus using Yld2000-2d yield model

2019 ◽  
Vol 267 ◽  
pp. 289-307 ◽  
Author(s):  
Shamik Basak ◽  
Sushanta Kumar Panda
Keyword(s):  
Plastic Strain ◽  
Effective Plastic Strain ◽  
Yield Model ◽  
Sheet Materials

A Finite Element Model of Orthogonal Metal Cutting

1985 ◽  
Vol 107 (4) ◽  
pp. 349-354 ◽  
Author(s):  
J. S. Strenkowski ◽  
J. T. Carroll
Keyword(s):  
Finite Element ◽  
Plastic Strain ◽  
Residual Stresses ◽  
Finite Element Model ◽  
Metal Cutting ◽  
Element Model ◽  
Effective Plastic Strain ◽  
Orthogonal Metal Cutting ◽  
Chip Separation ◽  
Chip Geometry

A finite element model of orthogonal metal cutting is described. The paper introduces a new chip separation criterion based on the effective plastic strain in the workpiece. Several cutting parameters that are often neglected in simplified metal-cutting models are included, such as elastic-plastic material properties of both the workpiece and tool, friction along the tool rake face, and geometry of the cutting edge and workpiece. The model predicts chip geometry, residual stresses in the workpiece, and tool stresses and forces, without any reliance on empirical metal cutting data. The paper demonstrates that use of a chip separation criterion based on effective plastic strain is essential in predicting chip geometry and residual stresses with the finite element method.

scholarly journals Elasto-plastic analysis of the contact region between a rigid ellipsoid and a semi-flat surface

2018 ◽  
Vol 10 (9) ◽  
pp. 168781401879739 ◽  
Author(s):  
Pengyang Li ◽  
Lingxia Zhou ◽  
Fangyuan Cui ◽  
Quandai Wang ◽  
Meiling Guo ◽  
...  
Keyword(s):  
Residual Stress ◽  
Plastic Deformation ◽  
Plastic Strain ◽  
Contact Pressure ◽  
Contact Region ◽  
Three Dimensional ◽  
Von Mises Stress ◽  
Effective Plastic Strain ◽  
Normal Forces ◽  
Von Mises

When the load acting on a mechanical structure is greater than the yield strength of the material, the contact surface will undergo plastic deformation. Cumulative plastic deformation has an important influence on the lifespan of mechanical parts. This article presents a three-dimensional semi-analytical model based on the conjugate gradient method and fast Fourier transform algorithm, with the aim of studying the characteristic parameters of the contact region between a rigid ellipsoid and elasto-plastic half-space. Moreover, normal forces and tangential traction were considered, as well as the contact pressure resulting from various sliding speeds and friction coefficients. The contact pressure, effective plastic strain, von Mises stress, and residual stress were measured and shown to increase with increasing sliding velocity. Finally, when the friction coefficient, contact pressure, and effective plastic strain are increased, the von Mises stress is also shown to increase, whereas the residual stress decreases.

The Forging Penetration Efficiency of C45 Steel Stepped Shaft Radial Forging with GFM Forging Machine

2010 ◽  
Vol 154-155 ◽  
pp. 593-596 ◽  
Author(s):  
Xiang Ru Liu ◽  
Xu Dong Zhou
Keyword(s):  
Plastic Strain ◽  
Compressive Strain ◽  
Three Dimensional ◽  
Mean Stress ◽  
Radial Forging ◽  
Effective Plastic Strain ◽  
Forging Process ◽  
Stepped Shaft ◽  
Radial Forging Process ◽  
Strain Layer

The numerical thermal mechanical simulation of radial forging process of C45 steel stepped shaft with GFM forging machine was carried out by three dimensional finite element method DEFORM 3D. According to effective plastic strain, mean stress and mean plastic strain distribution of the radial forging process, the forging penetration efficiency (FPE) was studied throughout. The results show that: effective plastic strain in the center of the forging is never be zero; The mean stress in the center of the workpiece is proposed to describe hydrostatic pressure in this paper. There is compressive strain layer beneath the surface of the workpiece, while there is tensile strain layer in the center of the forging. These studied results could be a valuable reference for designing the similar forging operations.

scholarly journals Numerical Investigation of Plastic Strain Homogeneity during Equal-Channel Angular Pressing of a Cu-Zr Alloy

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1505
Author(s):  
Jittraporn Wongsa-Ngam ◽  
Nitikorn Noraphaiphipaksa ◽  
Chaosuan Kanchanomai ◽  
Terence G. Langdon
Keyword(s):  
Steady State ◽  
Plastic Strain ◽  
Equal Channel Angular Pressing ◽  
Fem Simulation ◽  
Effective Plastic Strain ◽  
3D Fem ◽  
Cross Sectional ◽  
Angular Pressing ◽  
Strain Homogeneity ◽  
Zr Alloy

A three-dimensional finite element method (3D FEM) simulation was carried out using ABAQUS/Explicit software to simulate multi-pass processing by equal-channel angular pressing (ECAP) of a circular cross-sectional workpiece of a Cu-Zr alloy. The effective plastic strain distribution, the strain homogeneity and the occurrence of a steady-state zone in the workpiece were investigated during ECAP processing for up to eight passes. The simulation results show that a strain inhomogeneity was developed in ECAP after one pass due to the formation of a corner gap in the outer corner of the die. The calculations show that the average effective plastic strain and the degree of homogeneity both increase with the number of ECAP passes. Based on the coefficient of variance, a steady-state zone was identified in the middle section of the ECAP workpiece, and this was numerically evaluated as extending over a length of approximately 40 mm along the longitudinal axis for the Cu-Zr alloy.

scholarly journals Matrix Stress-strain Working Method for Determining the Effective Plastic Strain

2015 ◽  
Vol 132 ◽  
pp. 381-388
Author(s):  
M. Sánchez-Carrilero ◽  
M. Álvarez ◽  
P. Mayuet ◽  
A. Gómez-Parra ◽  
M. Marcos
Keyword(s):  
Plastic Strain ◽  
Effective Plastic Strain ◽  
Stress Strain ◽  
Matrix Stress ◽  
Working Method

Numerical study on the interfacial behavior of Mg/Al plate in explosive/impact welding

2017 ◽  
Vol 24 (4) ◽  
pp. 581-590 ◽  
Author(s):  
Xiaodan Yuan ◽  
Wenxian Wang ◽  
Xiaoqing Cao ◽  
Tingting Zhang ◽  
Ruishan Xie ◽  
...  
Keyword(s):  
Shear Stress ◽  
Plastic Strain ◽  
Numerical Study ◽  
Welding Process ◽  
Base Plate ◽  
Oblique Impact ◽  
Physical Parameters ◽  
Interfacial Behavior ◽  
Effective Plastic Strain ◽  
Particle Hydrodynamics

AbstractIn this study, the process of explosive welding of Mg/Al plate is represented, and the interfacial behavior of two metals is researched. The objective of this work is to investigate the factors that affect the quality of explosive bonding and the distribution of physical parameters on the collision. A finite difference engineering package with smoothed particle hydrodynamics method is used to model the oblique impact of a thin flyer plate (Al) on a relatively thick base plate (Mg). Wavy interface and jetting phenomenon, which existed in the experiment, are well reproduced in the simulation. The contours of pressure, shear stress, velocity, and effective plastic strain of magnesium and aluminum are also distinctly described. The bonding turns out to be a possible solid-state welding process. The effective plastic strain exceeds a minimum value, and the shear stress is just the opposite sign in this simulation where available bonding occurred. Wave formation appears to be the result of variation in the velocity distribution on the interface and periodic disturbances of magnesium and aluminum. A transition from straight to wave occurs along the interface. High values of plastic strain of two metals are predicted on the interface.

scholarly journals Effect of Curvature on Penetration Resistance of Polycarbonate Panels

2016 ◽  
Vol 83 (12) ◽  
Author(s):  
G. O. Antoine ◽  
R. C. Batra
Keyword(s):  
Hydrostatic Pressure ◽  
Plastic Strain ◽  
Strain Rate ◽  
Penetration Resistance ◽  
Plastic Strain Rate ◽  
Radius Of Curvature ◽  
Effective Plastic Strain ◽  
Flat Plates ◽  
Curved Panels ◽  
Positively Curved

Three-dimensional transient deformations of clamped flat and doubly curved polycarbonate (PC) panels impacted by a rigid smooth hemispherical-nosed circular cylinder have been numerically studied by the finite-element (FE) method to delineate effects of the panel radius of curvature to its thickness ratio on their penetration resistance. The PC is modeled as thermoelastoviscoplastic with the effective plastic strain rate depending upon the hydrostatic pressure. The effective plastic strain of 3.0 at failure is ascertained by matching for one set of flat panels the computed and the experimental minimum perforation speeds. It is found that a negative curvature (i.e., the center of curvature toward the impactor) of a panel degrades its penetration performance, and the positive curvature enhances it especially for thin panels with thickness/radius of curvature of 0.01. However, the benefit is less evident for panels with the panel thickness/radius of curvature of 0.04 or more. For positively curved thin panels, an elastic hinge forms around the central impacted area during an early stage of deformations, and subsequent deformations occur within this region. No such hinge is observed for flat plates, negatively curved panels of all the thicknesses, and positively curved thick panels. Furthermore, the maximum effective stress induced in regions surrounding the impacted area is less for positively curved panels than that for flat panels. The dominant failure mechanism is found to be the deletion of failed elements due to the effective plastic strain in them exceeding 3.0 rather than due to plug formation. For an example problem, the dependence of the effective plastic strain rate upon the hydrostatic pressure and the consideration of the Coulomb friction at the contact surfaces exhibited minimal effects on the penetration characteristics. This information should be useful for designers of impact-resistant transparent armor, such as an airplane canopy, automobile windshield, and goggles.

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