The paper evaluates the limitations that semielliptical surface crack in a shaft is simplified to a unilateral crack in a finite boundary plane and a cross straight line crack in a semiinfinitebody.
It is shown that the damping value established from three parameter model is smaller than that of two parameter model or elastic semi-infinitebody theory.
由该模型的分析结果表明，其阻尼值比之按两参数模型以及按弹性半空间体的理论模型求得的值要小得多。
3
In this paper, the finite difference method is used to analise the mat foundation based on semi-infinite elastic body, and an improved suggestion about how to deal with the noriregul.