粘弹性介质中扩展裂纹与J积分

本文提出了在线弹性及粘弹性介质中扩展裂纹与路径无关的J~*积分,并给出了严密的证明。文中证明了J~*积分与扩展裂纹尖端的张开位移(动态COD)之间有简单的关系,同时利用J~*积分求得了粘弹性介质中变速扩展裂纹尖端的奇异性。当裂纹以常速扩展时,J~*积分与能量释放率、动应力强度因子之间也有简单的关系。利用这些关系,我们给出了动态COD与动应力强度因子之间的关系式。

PROPAGATING CRACK AND J INTEGRAL IN VISCOELASTIC BODY

This paper gives a strict mathematical proof to the J~* integral which is shown by the moving coordinate system in linear-elastic and viscoelastic bodies. It also proves that there is a simple relation between the J~* integral and dynamic crack opening displacement in viscoelastic body. The singularity of propagating crack tip in viscoelastic body is obtained by the use of the J~* integral. When the crack propagates at constant speed, there also exist simple relations between the J~* integral and energy release rate,and dynamic stress intensity factor.By using these relations, we gave the relation between dynamic COD and dynamic stress intensity factor.