以应变能密度原理估计缺口底部局部应力应变

Energy Density Approach to Calculation of Local Stress-Strain at Notches Tip

本文介绍了根据应变能密度原理估计拉载作用下缺口底部应力、应变的方法。缺口底部塑性区的应变能密度可由弹性应力—应变关系导出。当缺口底部局部屈服后,通过应力重新分布修正,可以得到较为理想的理论解。文中提供了求解局部应力应变的数值计算过程,并进行了三种几何形状缺口,在拉载作用下局部应变实测。局部应变的数值计算值与实测结果能较好地吻合。

An application of the equivalent strain energy density method for calculation of elastic-plastic notch-tip strains under tension loading is presented. It is assumed that the strain energy density in the plastic zone ahead of a notch can be calculated on the basisof the elastic stress-strain solution. The theoretical notch-tip strain calculatons can be improved, if the stress redistribution due to the plastic yielding around the notch tip istaken into acound. A numerical procedure for calculating local stress and strain at notch tip is presented in the paper and the measurements of local strain at three kinds of notch tip in tension are done. The agreement between the calculated and measured strains is good.