前混合水射流多弹丸喷丸模型及残余应力场的数值模拟

Numerical Simulation of Multi-shot Shot Peening Models and Residual Stress Field of Premixed Water Jet

针对前混合水射流的液固湍动特性与喷丸过程多重非线性耦合作用行为,提供一种射流喷丸强化残余应力场的有限元分析法。采用液固两相流动理论与计算流体动力学方法分析喷嘴内流特性,建立射流多弹丸喷丸模型;基于弹丸速度冲击载荷加载制度,利用多线性各向同性强化弹塑性模型,应用动态接触对称罚函数法,运用ABAQUS软件模拟不同弹丸数量作用下射流喷丸在45钢材料表层产生的残余应力场,获得残余应力场的分布规律及残余应力沿深度的变化规律;得出射流喷嘴内流呈均质流流型,不同弹丸数量射流喷丸在材料表层产生的径向残余应力沿深度的变化规律相同,但在材料表面产生的径向残余压应力值受喷丸模型影响较大,对弹丸分三层排列、相邻弹丸之间径向和周向中心距离均为弹丸半径的多弹丸喷丸模型,数值模拟获得的表面径向残余压应力值与射流喷丸试验数据基本吻合。

In view of the liquid-solid turbulence behavior of premixed water jet and multiple nonlinear coupling behavior in shot peening process,an analysis method of finite element for jet peening strengthening residual stress field is provided in this article.The liquid-solid two-phase flow theory and computational fluid dynamics method are used to analyze the internal flow characteristics of the nozzle,and the jet shot peening model of multiple projectiles is established.Based on projectile speed impact load loading system,an elastic-plastic model with multilinear isotropic hardening and dynamic contact symmetric penalty function method are adopted,and the finite element software ABAQUS is used to simulate the residual stress fields produced on the surface layer of 45 steel by jet peening under different number of projectiles,thereby the distribution law of residual stress field and the variation law of residual stress along depth are revealed.It is found that the internal flow of the jet nozzle presents a homogeneous flow pattern.The variation law of the radial residual stress along the depth produced by different number of projectiles jet peening on the surface layer of the material is the same.But the radial residual pressure stress value on the surface of the material is greatly affected by the shot peening model,for the multiple projectile shot peening model,whose projectiles are arranged in 3 layers,the radial and circumferential center distance between adjacent projectiles are all the radius of the projectile,the surface radial residual pressure stress value calculated by numerical simulation is proximate to the test data of jet shot peening.