Contact Analyses for Bodies With Frictional Heating and Plastic Behavior

2005 ◽  
Vol 127 (2) ◽  
pp. 355-364 ◽  
Author(s):  
Vincent Boucly ◽  
Daniel Ne´lias ◽  
Shuangbiao Liu ◽  
Q. Jane Wang ◽  
Leon M. Keer
Keyword(s):  
Stress Field ◽  
Thermal Stresses ◽  
Frictional Heating ◽  
Equivalent Plastic Strain ◽  
Engineering Application ◽  
Von Mises Stress ◽  
Normal Displacement ◽  
Plastic Behavior ◽  
Important Indicator ◽  
Elastic Plastic

The stress field within machine components is an important indicator for contact failures. Since both thermal stresses due to frictional heating and plasticity are significant in engineering application, it is critical to predict the total stress field. In this work, the steady-state thermal effect is considered and a thermo-elastic–plastic contact model is developed. The model is applicable for rolling and/or sliding contact problem, as far as small equivalent plastic strain hypothesis is respected. Influence coefficients for surface normal displacement, temperature, and strain and stress tensors are used with the discrete convolution and fast Fourier transform algorithm. The single-loop conjugate gradient iteration scheme is also applied to achieve fast convergence speed. Simulations are presented for several academic examples ranging from elastic to thermo-elastic–plastic. The thermo-elastic–plastic analyses show that the heat factor in a contact situation has significant effect not only on the critical Hertzian pressure and on the pressure distribution, but also on the magnitude and depth of the maximum von Mises stress during loading and the residual ones found after unloading.

Contact Analyses for Bodies With Frictional Heating and Plastic Behavior

2005 ◽  
Author(s):  
V. Boucly ◽  
D. Ne´lias ◽  
S. Liu ◽  
Q. J. Wang ◽  
L. M. Keer
Keyword(s):  
Stress Field ◽  
Thermal Stresses ◽  
Frictional Heating ◽  
Equivalent Plastic Strain ◽  
Engineering Application ◽  
Iteration Scheme ◽  
Normal Displacement ◽  
Plastic Behavior ◽  
Important Indicator ◽  
Influence Coefficients

The stress field within machine components is an important indicator for contact failures. Since both thermal stresses due to frictional heating and plasticity are significant in engineering application, it is critical to predict the total stress field. In this work, the steady- state thermal effect is considered and a thermo-elastic-plastic contact model is developed. The model is applicable for rolling and/or sliding contact problem, as far as small equivalent plastic strain hypothesis is respected. Influence coefficients for surface normal displacement, temperature, and strain and stress tensors are used with the discrete convolution and fast Fourier transform algorithm. The single-loop conjugate gradient iteration scheme is also applied to achieve fast convergence speed. Simulations are presented for several academic examples ranging from elastic to thermoelastic-plastic.

Residual Stress Regenerated on Low Plasticity Burnished Inconel 718 Surface After Initial Turning Process

2019 ◽  
Vol 141 (12) ◽  
Author(s):  
Yang Hua ◽  
Zhanqiang Liu ◽  
Bing Wang ◽  
Jiaming Jiang
Keyword(s):  
Residual Stress ◽  
Stress Field ◽  
Analytical Model ◽  
Inconel 718 ◽  
Plastic Behavior ◽  
Residual Stress Field ◽  
Workpiece Material ◽  
Elastic Plastic ◽  
Initial Residual Stress ◽  
Low Plasticity Burnishing

Abstract Low plasticity burnishing (LPB) has been extensively employed in aero-industry to enhance fatigue performance of machined components by introducing compressive residual stress. Effects of various parameters on the residual stress field induced by low plasticity burnishing have been investigated by many researchers. However, initial residual stresses induced by machining are one of the important factors which affect the residual stress regenerated by the LPB process. The present work aims to develop an analytical model which takes into account the initial residual stress and burnishing parameters to predict residual stress field of workpiece material Inconel 718 based on Hertz contact theory and elastic–plastic theory. Initial residual stress fields were produced by turning of Inconel 718 and were measured by using X-ray diffraction technique. Two types of material constitutive models such as the linear hardening model and isotropic–kinematic model were employed to describe the elastic–plastic behavior of workpiece material Inconel 718. An analytical study was performed to analyze the effect of the initial residual stress field and burnishing parameters on residual stress induced by low plastic burnishing. The results of analytical model were verified by conducting the LPB experiments on initial turned Inconel 718. The results showed that the shape and magnitude of the residual stress field obtained with considering the effect of initial residual stress field was in good accordance with experimental measurements.

Numerical Study on Elastic-Plastic Stress Field Near the Cooling Holes of Nickel-Based Single Crystal Air-Cooled Blades

2006 ◽  
Vol 324-325 ◽  
pp. 563-566 ◽  
Author(s):  
Qing Min Yu ◽  
Zhu Feng Yue ◽  
Yong Shou Liu
Keyword(s):  
Shear Stress ◽  
Stress Field ◽  
Numerical Study ◽  
Von Mises Stress ◽  
Shear Stresses ◽  
Slip Systems ◽  
Stress Distributions ◽  
Elastic Plastic ◽  
Von Mises ◽  
Plastic Stress

In this paper, a plate containing a central hole was used to simulate gas turbine blade with cooling hole. Numerical calculations based on crystal plasticity theory have been performed to study the elastic-plastic stress field near the hole under tension. Two crystallographic orientations [001] and [111] were considered. The distributions of resolved shear stresses and strains of the octahedral slip systems {110}<112> were calculated. The results show that the crystallographic orientation has remarkable influence on both von Mises stress and resolved shear stress distributions. The resolved shear stress distributions around the hole are different between the two orientations, which lead to the different activated slip systems. So the deformed shape of the hole in [001] orientation differs from that in [111] orientation.

Rolling of an Elastic Ellipsoid Upon an Elastic-Plastic Flat

2007 ◽  
Vol 129 (4) ◽  
pp. 791-800 ◽  
Author(s):  
Daniel Nélias ◽  
Eduard Antaluca ◽  
Vincent Boucly
Keyword(s):  
Surface Deformation ◽  
Normal Load ◽  
Permanent Deformation ◽  
Computing Time ◽  
Equivalent Plastic Strain ◽  
Numerical Procedure ◽  
Theoretical Background ◽  
Rolling Contact ◽  
Von Mises Stress ◽  
Elastic Plastic

The paper presents a numerical analysis of the rolling contact between an elastic ellipsoid and an elastic-plastic flat. Numerical simulations have been performed with the help of a contact solver called Plast-Kid®, with an algorithm based on an integral formulation or semi-analytical method. The application of both the conjugate gradient method and the discrete convolution and fast Fourier transform technique allows keeping the computing time reasonable when performing transient 3D simulations while solving the contact problem and calculating the subsurface stress and strain states. The effects of the ellipticity ratio k—ranging from 1 to 16—and of the normal load—from 4.2 GPa to 8 GPa—are investigated. The reference simulation corresponds to the rolling of a ceramic ball on a steel plate made of an AISI 52100 bearing steel under a load of 5.7 GPa. The results that are presented are, first, the permanent deformation of the surface and, second, the contact pressure distribution, the von Mises stress field, the hydrostatic pressure, and the equivalent plastic strain state within the elastic-plastic body. A comparison with an experimental surface deformation profile is also given to validate the theoretical background and the numerical procedure.

Elastic-Plastic Plane-Strain Solutions With Separable Stress Fields

1969 ◽  
Vol 36 (3) ◽  
pp. 528-532
Author(s):  
D. B. Bogy
Keyword(s):  
Stress Field ◽  
Plane Strain ◽  
Yield Criterion ◽  
A Priori ◽  
Equivalent Plastic Strain ◽  
Uniaxial Stress ◽  
Stress Fields ◽  
Isotropic Hardening ◽  
Flow Rule ◽  
Elastic Plastic

A stress field σij(χ, t) depending on position χ and time t will be called separable if the time-dependence enters only through a scalar multiplier; i. e., if σij(χ,t)=s(χ,t)σˆij(χ). It is shown here that elastic-plastic plane-strain solutions in the infinitesimal (flow) theory of plasticity satisfying Tresca’s yield criterion and associated flow rule with linear isotropic hardening, based on either equivalent plastic strain or total plastic work, can occur with separable stress fields only in the following instances: (a) solutions with uniaxial stress fields, as in bending, (b) solutions with stress fields such that the entire domain changes from elastic to plastic at the same time, and (c) solutions with stress fields for which the elastic-plastic boundary coincides with a principal shear stress trajectory. Whether or not a plasticity solution has a separable stress field can be determined a priori by examining the corresponding elasticity solution.

Rolling of an Elastic Ellipsoid Upon an Elastic-Plastic Flat

2007 ◽  
Author(s):  
D. Ne´lias ◽  
E. Antaluca ◽  
V. Boucly
Keyword(s):  
Surface Deformation ◽  
Normal Load ◽  
Permanent Deformation ◽  
Equivalent Plastic Strain ◽  
Numerical Procedure ◽  
Bearing Steel ◽  
Theoretical Background ◽  
Rolling Contact ◽  
Von Mises Stress ◽  
Elastic Plastic

The paper presents a numerical analysis of the rolling contact between an elastic ellipsoid and an elastic-plastic flat. Numerical simulations have been performed with the help of a contact solver called Plast-Kid®, with an algorithm based on an integral formulation or semi-analytical method. The effects of the ellipticity ratio k — ranging from 1 to 16 — and of the normal load — from 4.2 to 8 GPa — are investigated. The reference simulation corresponds to the rolling of a ceramic ball on a steel plate made of AISI 52100 bearing steel under a load of 5.7 GPa. The results which are presented are first the permanent deformation of the surface, and second the contact pressure distribution, the Von Mises stress field, the hydrostatic pressure and the equivalent plastic strain state within the elastic-plastic body. A comparison with an experimental surface deformation profile is also given to validate the theoretical background and the numerical procedure.

Elastic-plastic behavior of coldworked holes

1983 ◽  
Author(s):  
H. ARMEN ◽  
A. LEVY ◽  
H. EIDINOFF
Keyword(s):  
Plastic Behavior ◽  
Elastic Plastic

An Adaptive EFG-FE Computational Model for Thermal Elasto-Plastic Frictional Contact Problems

2008 ◽  
Vol 33-37 ◽  
pp. 821-826
Author(s):  
Zheng Zhang ◽  
Geng Liu ◽  
Tian Xiang Liu
Keyword(s):  
Frictional Heating ◽  
Contact Problems ◽  
Coupling Model ◽  
Adaptive Refinement ◽  
Frictional Heat ◽  
Plastic Behavior ◽  
Initial Stiffness ◽  
Gradient Based ◽  
Local Adaptive Refinement ◽  
The Cost

An adaptive meshless element-free Galerkin-finite element (EFG-FE) coupling model for thermal elasto-plastic contact problems is developed to investigate the influences of the steady-state frictional heating on the contact performance of two contacting bodies. The thermal elasto-plastic contact problems using the initial stiffness method is presented. The local adaptive refinement strategy and the strain energy gradient-based error estimation for EFG-FE coupling method are combined. The adaptive meshless model takes into account the temperature variation, micro plastic flow, and the coupled thermo-elasto-plastic behavior of the materials, considering the strain-hardening property of the materials and temperature-dependent yield strength. The adaptive model is verified through the contact analysis of a cylinder with an elasto-plastic plane. The thermal effects on the contact pressure, stresses distributions with certain frictional heat inputs are studied. The results show that the accuracy of the solutions from the adaptive refinement model is satisfactory but the cost of the CPU time is much less than that for the uniform refinement calculation.

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