采用壳体应变—应力状态的体—壳过渡元

 由于初始热应变表达式不当及不能完全实现泊松效应,以往建立的体-壳过渡元会导致不真实的大应力。本文采用壳体应变-应力状态作为过渡元中的应变应力状态,给出~种新的15节点体-壳过渡元列式,从而解决了以上两个方面的问题。算例表明了这种过渡元的有效性与实用性。本文方法既适用于其它类型的过渡元,对于其它处理体-壳组合结构的方法也有重要参考价值。

SOLID-SHELL TRANSIENT ELEMENT WITH SHELL STRAIN-STRESS STATE

The solid-shell transient elements established before will cause an unrealistic high level of stress because of using a wrong expression for the initial thermal strain and restricting the Poisson's effect for the material in the element. To solve both problems, in this paper, a new formulation for the 15-node solid-shell transient element is given by choosing the shell strain-stress state as the strain-stress state of the transient element. The expression for the coordinate, the displacement, the strain and the stress in the local coordinate system, the stiffness matrix, and the load vector are derived in detail. Numerical examples for the turbine rotor blades of two aeroengines are given at the end of the paper. The results of one of the examples are compared with the corresponding experimental results. These examples have shown the effectiveness of this new type of transient element. The present technique can also be applied to other types of transient elements and methods dealing with the solid-shell combined structures.