16MnR二维弹塑性J积分计算方法研究

针对我国常用压力容器用钢１６ＭｎＲ长屈服增台，屈服后又明显硬化的特点。采用拟牛法编制了微机用二维弹性Ｊ积分计算有限元程序，并进行了精度考核，在非线性方程组的求解方法上，采用了拟牛顿法，并且根据积分围线的不同定义，分别沿单元边界积分和沿单元内高斯点积分计算Ｊ积分。数值算例表明：拟牛顿法有效了提高了非线性方程组的求解速度，其精度与ＥＰＲＩ法相比，偏差在５％之内，而且是偏于安全的，基于符合工程要求。

A Study on Calculation Method of 2-D Elastic-Plastic J-integral of 16MnR

This paper presents a 2 - D elastic - plastic J - integral estimating Finite ElemcntProgram for personal computers, in which the methed of Quasi - Newton - Raphson (QNR) isapplied to deal with the long - yield plateau and stress hardening problem of the material of16MnR, a commonly used material for pressure vessels in China. Additionally, two different J- integreals are made both along the element boundary and the Gauss Points in the elements.The results showed that QNP method is conservative, and it can raise the calculating speeed notably, The error of this method is within 5% campared to that of EPRI and can be safly appliedin Engineering. The paper provided a way to use FAC which based on J - integral in China.