应用增量理论考虑应变硬化效应包辛格效应和温度对机械性质影响的自增强厚壁圆筒分析

本文提出的采用增量理论的分析模型和方法可以定量分析应变硬化、包辛格效应和材料机械性质随温度变化等因素对自增强厚壁圆筒中残余应力和操作应力分布的影响.厚壁圆筒看成由N个同轴薄壁圆筒套在一起组成的构件;采用包括弹性、塑性和温度应变的增量型本构关系和相容条件导出了自增强圆筒的基本方程;设计了计算机程序并给出了分析实例。分析结果表明,应变硬化会减小塑性区并降低残余应力;包辛格效应使反向屈服容易出现;温度升高将使残余应力和热应力松驰.

AN ANALYSIS OF AUTOFRETTTAGED CYLINDER BY APPLYING INCREMENTAL THEORY AND CONSIDERING THE INFLUENCES OF THE STRAIN-HARDENING EFFECT, BAUSCHINGER EFFECT AND TEMPRATURE DEPENDENCE OF MATERIAL PROPERTIES

In this paper, a new model and an incremental method ard presented. Employing which, the influences of some factors such as the effect of strain-hardening, Bauschinger effect and the temperature dependence of material properties, on distributions of residual and working stresses in a autofrettaged cylinder could be quantitatively estimated. the thin-wall cylinder is fictitiously divided into N layers of coaxial thin-wall cylinders. Constitutive equations and equations of compatibility, which are all of incremental type and include elastic, plastic and thermal strains, are used to derive the governing equations of the autofrettaged cylinder. Computer program has been designed and a numerical example is given. The results conclude that the strain-hardening effect decreases the plastic range and residual stresses, the Bauschinger effect makes reverse yield easier and temperature rise will relax the residual stresses and thermal stresses.The developed method can also be extended to consider nonlinear strainhardening, nonlinear temperature dependence of material properties and creep effect.