多轴应力应变的一种新的计算方法

NEW METHOD FOR CALCULATING ELASTO-PLASTIC STRAINS AND STRESSES UNDER MULTIAXIAL LOADING

计算缺口件缺口处的应力应变方法有多种 ,其中应用较广的是具有能量观点的Neuber法和等效应变能密度法。通常Neuber法过高地估计应力和应变 ,等效应变能密度法过低地估计应力和应变。通过分析研究 ,文中引进屈服强度参数 ,提出一种新的计算方法。通过对同一构件缺口处的应力应变的计算结果进行比较可知 ,文中提出的新的计算方法是合理可行的 。

Many methods that may apply to calculate the strains and stresses of notches have been presented. In generally Neuber's rule and equivalent strain energy density (ESED) method were widely used, which have certain physical meaning. Neuber's rule tends to overestimate stresses and strains. Contrary to Neuber's rule, ESED method usually underestimates stresses and strains. The authors investigate the problem and put forward a new approach by making use of yield stress. The new method is the same as Neuber's rule when the notches are in elastic state, but in plastic they are different. A notch tip stresses and strains have been calculated by adopted the three methods and finite element method (FEM). The results show that the new approach is more reasonable.