粘弹性界面裂纹奇异场

对于许多粘弹性问题,通常可以利用对应性原理,即由弹性问题的结果得到对应的粘弹性问题在拉普拉斯变换域内的解,再通过反演变换求得最终时域中的解.但是,由于界面裂纹场存在着振荡奇异性,弹性问题解的形式就已经非常复杂,对应的粘弹性问题要通过反演变换直接求得准确的解析解几乎是不可能的.本文在利用对应性原理时做了更简单的准静态处理,即将弹性结果中的材料参数用粘弹性材料参数做对应替代,得到了粘弹性界面裂纹场近似的经典解,并与有限元分析结果作了比较.同时,利用Comninou接触模型,对粘弹性界面裂纹在远场拉剪混合加载情况下的裂尖应力场和接触区做了考察,并与经典解作了比较.

Viscoelastic Fields near Interface Crack Tip

Correspondence principle is widely applied to solve viscoelastic problems,i.e.,the solutions in the Laplace field from the correspondent of elastic solutions,and the reversed solutions into time field by inverse transformation.However,the fields near an interface crack tip are so complicated that it is difficult to complete the exact Laplace reverse transformation.The correspondence principle in a simple way,so called "quasi-static processing" was applied,just replacing the material parameters in elastic solutions with viscoelastic parameters.The results are compared with FEM analysis.Meanwhile,an interface crack tip under mixed tensile and shear traction was also analyzed,by adopting Comninou contact model.