0
Research Papers

Polycrystal Plasticity Modeling of Cyclic Residual Stress Relaxation in Shot Peened Martensitic Gear Steel

[+] Author and Article Information
Rajesh Prasannavenkatesan

 QuesTek Innovations LLC, Evanston, IL 60201; George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0405

David L. McDowell1

 George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0405; School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0405david.mcdowell@me.gatech.edu

1

Corresponding author.

J. Eng. Mater. Technol 132(3), 031011 (Jun 18, 2010) (8 pages) doi:10.1115/1.4001594 History: Received November 24, 2009; Revised March 27, 2010; Published June 18, 2010; Online June 18, 2010

Using a three-dimensional crystal plasticity model for cyclic deformation of lath martensitic steel, a simplified scheme is adopted to simulate the effects of shot peening on inducing initial compressive residual stresses. The model is utilized to investigate the subsequent cyclic relaxation of compressive residual stresses in shot peened lath martensitic gear steel in the high cycle fatigue (HCF) regime. A strategy is identified to model both shot peening and cyclic loading processes for polycrystalline ensembles. The relaxation of residual stress field during cyclic bending is analyzed for strain ratios Rε=0 and 1 for multiple realizations of polycrystalline microstructure. Cyclic microplasticity in favorably oriented martensite grains is the primary driver for the relaxation of residual stresses in HCF. For the case of Rε=1, the cyclic plasticity occurs throughout the microstructure (macroplasticity) during the first loading cycle, resulting in substantial relaxation of compressive residual stresses at the surface and certain subsurface depths. The initial magnitude of residual stress is observed to influence the degree (percentage) of relaxation. Describing the differential intergranular yielding is necessary to capture the experimentally observed residual stress relaxation trends.

FIGURES IN THIS ARTICLE
<>
Copyright © 2010 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Variation in experimentally measured equibiaxial residual stress (σzz,0res,σxx,0res) with depth after shot peening

Grahic Jump Location
Figure 2

Hierarchical lath martensite microstructure

Grahic Jump Location
Figure 3

(a) Schematic showing a metallic ball impacting the specimen surface during shot peening, causing constrained plastic deformation extending to a depth Dp below the surface, and (b) the volume of the plastic zone divided into several subsurface volume elements; each with thickness L2 and corresponding to a depth D below the surface, where shot peening and fatigue simulations are performed

Grahic Jump Location
Figure 4

Methodology to simulate shot peening process: (a) schematic showing a subsurface element on which the strains are imposed, (b) σyy versus εyy response in the subsurface element during shot peening simulation, and (c) variation in elastic and plastic strain in X and Z directions in the subsurface element during shot peening

Grahic Jump Location
Figure 5

A typical finite element mesh of microstructure within a simulated subsurface volume element

Grahic Jump Location
Figure 6

Applied strain range as a function of depth during cyclic bending

Grahic Jump Location
Figure 7

Relation between the peak compressive strain (εyy,load) and the strain after unloading (εyy,unload) along surface normal direction Y during the shot peening simulation with depth

Grahic Jump Location
Figure 8

Relaxation of residual stress components at different depths during cyclic bending (normalized by their respective initial values after shot peening) for Rε=0 case along (a) Z direction and (b) X direction

Grahic Jump Location
Figure 9

Relaxation of residual stress components at different depths during cyclic bending (residual stresses are normalized by their respective initial values after shot peening) for Rε=−1 case along (a) Z direction and (b) X direction

Grahic Jump Location
Figure 10

Stress-strain response along cyclic bending stress direction (Z) at different subsurface depths during the first loading cycle following shot peening for (a) Rε=0 and (b) Rε=−1

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In