虚裂纹扩展法计算J积分的研究

本文将虚裂纹扩展法用于断裂问题的有限元分析，编制了计算二维Ⅰ型静态和动态Ｊ积分的程序，并对受静载的线弹性材料和线性硬化弹塑性材料的中。Ｃ裂纹问题以及受动载的线弹性材料中心裂纹问题进行了具体计算．将所得结果与位移外推法、直接积分法作了比较，表明采用虚裂纹扩展法计算Ｊ积分具有方法简单、精度很高、一致性好等优点．计算也表明，采用裂端楔形奇异单元可大大提高计算精度．

A Study on Virtual Crack Extension Method for Calculating J Integral

In this paper the virtual crack extension method is employed in the finite element analysis offracture problems.Two-dimensinnal calculations are Produced for a rectangular plate with a centralcrack under static or dynamic itals.The material of the plate in the septic cases is assumed to be elasticor elasto-planic with linear hsrdening, whereas in the dynamic case only elanic mat6rial is assumed.The value of J integtal calculated with this method is compared with that obtained using the method ofdisplacement extrapolation and the method of direct integration. The results show thst the virtual crackextension method is simpler, more accurate and consistent. The results also show that the accuracy canbe significantly increased by use of wedge-shaped singular elements adjacent to the crack tip.