To analyze residual stress of autofrettaged pressure vessels, APDL language of ANSYS was used to model its parametric FE, which was used to emulated the loading and unloading of autofrettaged pressure vessels by using multiple load step of ANSYS. Effects of end conditions of the vessel and material parameters on the residual stress were studied. The results show that end conditions have few effects on hoop residual stress and radial residual stress, and have bigger effects on axial residual stress in near the bore; the location of the greatest hoop stress depends on unloading tangent modulus, big unloading tangent modulus can improve the residual stress of near the bore. The studies used ANSYS BKIN (bilinear kinematic hardening) model to simulate loading and unloading of material mechanical properties by defining two temperature profiles for the material, and improve the prediction precision of the residual stress.

ultrahigh pressure vessel, residual stress, autofrettage, bilinear material, parameterization

为分析自增强超高压容器的残余应力,利用ANSYS的APDL语言开发了筒形超高压容器的参数化有限元模型,利用该模型并采用多载荷步法对容器自增强处理的加载过程和卸载过程进行了仿真。通过改变端部边界条件和材料参数研究了容器端部形式和材料参数对容器残余应力的影响。研究结果表明：端部形式对容器中部的周向应力和径向应力影响很小,对轴向应力影响较大,使轴向应力在内壁附近有较大的差别;切线模量不同,最大周向残余应力所在位置不同,大的卸载切线模量可以增大内壁处的周向残余应力。在ANSYS的BKIN材料模型下定义两种温度应力-应变曲线以分别模拟材料加载和卸载时的机械性能,准确地模拟了这类材料的应变硬化和鲍辛格效应,提高了残余应力预测的精度。

超高压容器, 残余应力, 自增强, 双线性材料, 参数化