16MnR钢裂纹体空穴扩张的有限元分析

FEM Analysis for Void Growth in 16MnR Steel Body with a Crack

本文采用弹塑性有限元方法,对16MnR钢的三点弯曲试件进行了应力应变分析,发现空穴扩张比V_G在裂尖前方存在一极大值,且V_G值随COD单调增加,文中指出,对高韧性材料,当裂尖前方V_G～y曲线的极大值达到某一临界值时,可作为主裂纹向前扩展的判据.

With a three-point-bending specimen of steel type 16MnR, stress and strain analyses have been carried out by the elastic-plastic finite element method. It is found that there exists a peak value of VG (void growth ratio) in the front of the crack tip and VG increases monotonically with COD. For highly ductile materials, when the maximum value of VG^y curve ahead of the crack tip reaches a critical value VGC, the void coalesces with the principal crack. It is the authors' view that the real cause of crack propagation lies in VGC, which can be taken as the criterion for crack propagation.