双轴加载下缺口应力应变分析的改进方法

A MODIFIED METHOD FOR CALCULATING STRESSES AND STRAINES OF NOTCH UNDER BIAXIAL LOADING CONDITION

已有的研究表明利用Neuber法以及等效应变能密度法(ESED法)计算缺口尖端应力应变时,前者计算的结果偏高,后者计算的结果偏低。而利用上述两种方法计算的结果分别为估算结果的上下限。基于对两种方法计算结果的分析,在Neuber法的基础上,改进其计算方法的不足,同时在改进的过程中考虑了材料特性(弹性模量、屈服强度以及泊松比)对应力应变估算结果的影响,同时又保证改进方法估算结果位于Neuber法和ESED法之间。以LD5缺口件为算例,利用改进方法估算其缺口根部应力应变结果,并将其与有限元结果进行对比,二者吻合度较好。

It has already been proved that the Neuber method overestimates the notch root stresses and strains and the equivalent strain energy density（ESED） method underestimates those,that is,the upper limit and lower limit can be obtained by the above two methods.On the basis of the analysis of results of notch root subjected to biaxial loading,a modified calculation method is proposed based on Neuber method in order to make up it＇s shortage.Meanwhile,in the case of plastic stage,the effect of the material constants of elastic modulus,yield stress and poisson＇s ratio on the stresses and strains should be considered and the results calculated by modified method should locate between those by Neuber method and the equivalent strain energy density method.Taking the LD5 notch sample as an example,the notch root stresses and strains are calculated.Finally the calculation results using modified method are validated with those by the finite element method.