Study On Finite Element Simulation Of Shot Peening Of Different Yield Strength Steeland Its Residual Stress

The shot pe ening mode l of low strength steel, medium strength steel, high strengthsteel and ultra high strength steel have been built with ANSYS/LS-DYNA finite elementsoftware in this paper, the simulation results and the residual stress distribut ion curve onmaterial depth coincide well with the actual shot peening situation, then the influence ofshot peening technology parameters such as the yield strength of material of the shot,shot radius, shot speed on residual stress field have been researched with the mode lsabove in this paper.Shot peening experiments andresidual stress measuring experimentsof different steel have also been done in this paper to provide the correlation data forsimulation.The simulation results of shot peening on these four different yield strength steelshows that the surface residual stress and the max residual stress bot h change in afluctuating way at the same pace and the same trends with the increase of shot speed andshot radius on the premise that the material of shot is determined, and in the curve of themax residual stress there exists an extreme value which is correspo nd with the actual shotpeening that the residual stress would reach max stress value with the shot peeningintensity increases, and the optimum shot speed and the optimum shot radius would bedetermined using the extreme value.After shot peening on these four different yield strength steel with shots of differentyield strength, the residua l stress field is studied and the results show that when the yieldstrength of shot increases, the depth of residual stress layer changes negligibly small, andthe surface residual stress and the max residual stress of shot peened low strength steelincrease greatly, but the residual stress of medium strength steel, high strength steel andultra high strength steel change insignificantly.The paper has researched the residual stress field of these four different steel shotpeened with shots of different radius, and finds that there is an approximate linearcorrelation be tween shot radius and depth of residual stress layer, the depth of residual stress layer increases attribute to the increase of shot radius. The paper also finds that aninflection point appears on the curve of residual stress layer depth and the residual stressgoes dow n slowly when there's an inflection point which leads to rapid decrease ofresidual stress on the curve of residual stress distribution on shot radius.The paper has shot peened these four different steel with shots of different speed bythe shot peening model, and finds that shot speed has a small influence on the residualstress layer depth of peened low strength steel which has low yield strength, but for theother steel as medium strength steel, high strength steel and ultra high strength steel, thedepth of residual stress layer increases in a fluctuating way with shot speed increases,meanwhile if there's an inflection po int appe ars on the curve of residual stressdistribution on shot speed and the residual stress decreases sharply, the depth of residualstress layer would increases gently or even goes do wn a little.Then the paper takes into account the yield strength of shot, shot radius and s hot speedcomprehensively and finds that residual stress remains the same when shot speed andshot radius keep constant which means shot energy keeps uncha nged, when shot speedincreases or shot radius increases which contribute to shot energy increases, the depth ofresidual stress increases correspondingly, and also the higher the yield strength of peenedmaterial, the greater influe nce shot energy would have on the depth of residual stress.The shot peening experiments and residual stress measuring experiments usingelectrochemistry layer technology have also been done in this paper, after comparison thepaper finds that the experiments results correlate well with the simulation results.