0
TECHNICAL PAPERS

# Development and Validation of Novel FE Models for 3D Analysis of Peening of Strain-Rate Sensitive Materials

[+] Author and Article Information
S. A. Meguid1

Engineering Mechanics and Design Laboratory, Department of Mechanical and Industrial Engineering, University of Toronto, 5 King’s College Road, Toronto, ON, M5S 3G8, Canadameguid@mie.utoronto.ca

G. Shagal, J. C. Stranart

Engineering Mechanics and Design Laboratory, Department of Mechanical and Industrial Engineering, University of Toronto, 5 King’s College Road, Toronto, ON, M5S 3G8, Canada

1

Corresponding author.

J. Eng. Mater. Technol 129(2), 271-283 (Aug 17, 2006) (13 pages) doi:10.1115/1.2712469 History: Received October 07, 2005; Revised August 17, 2006

## Abstract

In this paper, we provide two different symmetry cells to describe the shot-peening process. In this multiple impingement model, we study the dynamic behavior of TI-6Al-4V targets subjected to a large number of shots. Three-dimensional elastoplastic finite element analysis (FEA) of the process was conducted using these two symmetry cells for strain-rate sensitive targets and rigid shots. The basic symmetry cell is assigned a target surface area $C×C$, where $C$ is one half of separation distance between adjacent shots. The second “enhanced” symmetry cell is assigned a target surface area $2C×2C$ thus allowing higher density of impact point locations. Average residual stresses inside the target predicted by FEA were compared with experimental measurements using the hole-drilling technique. In order to do this, a new averaged technique was developed to obtain the stress distribution inside the symmetry cell. The results reveal that both symmetry cell models could be used for shot-peening modeling. However, the use of the enhanced symmetry cell leads to a better agreement with the measured residual stresses. In addition, the enhanced symmetry cell model allowed us to overcome some of the shortcomings of the basic symmetry cell for cases involving high peening velocity and intensity.

<>

## Figures

Figure 6

Discretized FE model of the enhanced symmetry cell

Figure 8

Residual stresses time history during the entire peening simulation for a point 40.8μm beneath the target surface on the center line of the first shot: (a) no strain-rate effects and (b) with strain-rate effects

Figure 9

Equivalent plastic strain-rate time history during the entire peening simulation for a point 40.8μm beneath the target surface on the center line of the first shot: (a) no strain-rate effects and (b) with strain-rate effects

Figure 10

Residual stress σxx contours (MPa) in peened target after first four rows of shots: (a) for the original and (b) for the enhanced symmetry cell

Figure 11

Residual stress σxx contours (MPa) in peened target after four series of shots: (a) for the original and (b) for the enhanced symmetry cell

Figure 12

Residual stresses (σxx) for different locations inside the original symmetry cell: (a) residual stress distributions and (b) location of plotted curves

Figure 13

Residual stress distributions inside the original symmetry cell: (a) no strain-rate effects and (b) with strain-rate effects

Figure 14

Residual stress distributions inside the enhanced symmetry cell with strain-rate effects after: (a) first, (b) second, (c) third, and (d) four series of shot impacts (25, 50, 75, and 100 shot impacts per cell, respectively)

Figure 15

Mean residual stress distributions inside the enhanced symmetry cell after each of four series of shot impacts: (a) no strain-rate effects and (b) with strain-rate effects

Figure 16

Polar distribution of normalized mean residual stresses near the surface region of the original symmetry cell: (a) no strain-rate effects and (b) with strain-rate effects

Figure 17

Effect of increased peening velocity v=40m∕s upon polar distribution of normalized mean residual stresses near the surface region of the original symmetry cell

Figure 18

Polar distribution of normalized mean residual stresses near the surface region of the enhanced symmetry cell without strain-rate effects after: (a) one and (b) four series of shot impacts

Figure 19

Comparison of predicted and measured residual stress distributions: (a) for the original and (b) for the enhanced symmetry cell

Figure 3

Peening schematic of the top surface of the enhanced symmetry cell for the first group of shot rows

Figure 2

Selected mesh of a symmetry cell with separation distance between adjacent shots C∕R=1

Figure 1

FE model of multiple impingement of multiple shots: (a) full model and (b) discretized FE model for one symmetry cell

Figure 7

Stress-strain relationship for Ti-6Al-4V: (a) quasi-static uniaxial stress-strain curve for minimum properties (σy0=120ksi) and (b) the normalized effective yield stress σy∕σy0 accounted for strain-rate sensitivity

Figure 5

Peening schematic of the top surface of the enhanced symmetry cell for the third group of shot rows

Figure 4

Peening schematic of the top surface of the enhanced symmetry cell for the second group of shot rows

## 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 Proceedings Articles
Related eBook Content
Topic Collections