某压气机轮盘均压孔挤压强化数值仿真和挤压头设计

采用静力学求解算法、应用弹塑性有限元分析程序对挤压强化过程进行了仿真计算,研究了摩擦因数、挤压次数、挤压量、约束方式、倒圆半径、以及配合方式等参数对残余应力场的影响.根据某压气机轮盘均压孔的具体结构形式,设计了三种挤压头:单侧挤压头、柱形头和T形头.用两种材料(不锈钢1Cr11Ni2W2MoV和镍基高温合金ЗП742)设计加工了带孔薄板模拟件,用其中两种强化方法对孔边进行了强化试验,试验结果表明:T形头挤压工艺达到了提高疲劳强度的预期效果,且操作方便实用.将试验结果和数值仿真结果进行了对比,分析表明用静力通用程序可以解决金属材料孔板挤压过程的仿真问题,能有效指导挤压强化研究. 

Simulation of extrusion strengthening of pressure equalizing hole of an engine compressor disc and design of extrusion heads

Statics solution algorithm was adopted in elastic-plastic finite element analysis program to simulate the extrusion strengthening process.Influences of parameters,such as friction coefficient,extrusion times,extrusion amount,restriction way,fillet radius and matching mode,on the residual stress distribution were analyzed.According to specific configuration of the pressure equalizing hole of the engine compressor disc,three different kinds of extrusion heads were designed,including:one-sided extrusion head,cylindrical extrusion head and T-shaped extrusion head.Two kinds of materials (stainless steel 1Cr11Ni2W2MoV and high temperature nickel-alloy ЗП742) were used to design and manufacture the simulation samples of sheets with holes.Edges of holes were strengthened using two above-mentioned coldworking techniques.The experiment results show that T-shaped extrusion techniques can efficiently and conveniently improve fatigue strength of sheets with holes.Numerical simulations were compared with experimental results,showing that statics general program can be used to simulate extrusion progress of sheet metal specimens with holes,and provide a guidance to extrusion strengthening research.