用裂纹张开位移计算三点弯曲试样的动态应力强度因子

CALCULATION OF DSIF OF THREE POINT BENDING SPECIMEN USING THE METHOD OF DCOD

给出了一种由裂纹的动态张开位移计算三点弯曲试样的动态应力强度因子的简单方法。对于两种不同几何尺寸的试样,在三类不同载荷作用下给出了数植算例,并与完全的动态有限元方法的计算结果进行了比较。结果表明:两种方法的计算结果相当一致。最后,还给出了由测定三点弯曲试样的裂纹张开位移确定试样的动态应力强度因子,最终确定材料动态起裂韧性的方法。

In this paper, a simple formula is derived for calculating the dynamic stress intensity factor (DSIF)of three point bending specimen using dynamic crack opening displacement (DCOD). The numerial examples are given for two kinds of specimens, which have different size, under three types of loading and compared with the results of dynamic finite element method. It is shown that the results of these two methods have a good agreement with each other. Finally, the experimental procedure of measuring the dynamic crack initiation toughness is proposed determining the dynamic crack opening displacement at first, then determining the dynamic stress intensity factor at the moment of crack initiation.