高应变率下Ⅱ型应力强度因子的数值模拟

Numerical simulation ofⅡtype stress intensity factor under high strain rate

文章采用有限元软件ANSYS/LS-DYNA程序对静态和冲击荷载作用下的含裂纹半圆弯曲（简称SCB）试验进行了数值模拟。根据静态试验的模拟结果,提出了静态荷载作用下的Ⅱ型应力强度因子拟合公式,其计算误差不超过10%。含复合型裂纹动态SCB试验的模拟结果表明：对于含复合型裂纹的动态加载的SCB试验,动态应力强度因子KⅡ随着试样半径R、裂纹倾角β以及相对裂纹长度a/R的变化呈现规律性变化。当相对裂纹长度a/R在0.4-0.6、裂纹倾角β在10°-40°范围内时,可以直接采用静态公式计算KⅡ,相对误差小于10%。

Finite element software ANSYS/LS-DYNA program was used in the numerical simulation of semi-circular bending（SCB） test with crack under static and impact loading. According to the simulation result of static test, the fitting formula of II type stress intensity factor under static loading is put forward and the maximum error is less than 10%. The simulation result of dynamic SCB test with mixed-mode crack shows that for the SCB test with mixed-mode crack under dynamic loading, the dynamic stress intensity factor Kn shows regular changes with the change of specimen radius R, crack angle β and relative crack length a/R. When the relative crack length a/R is from 0.4 to 0. 6 and the crack angle β is from 10° to 40°, KII is calculated with the static fitting formula and the relative error is less than 10%.