二三维连续介质分析中的等效弹簧元
THE EQUIVALENT SPRING ELEMENTS TO THE ANALYSIS OF TWO AND THREE DIMENSIONAL CONTINUUM
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摘要: 该文给出了一类将二维和三维连续介质等效成弹簧元体系进行分析的研究思路,并将二维和三维的等效弹簧单元应用于容器结构与内部连续介质相互作用的静力与动力分析中。首先,该文给出了基于刚度等效原理的二维与三维等效弹簧元理论。其次,利用二维等效弹簧元模型作为基本单元分析了连续介质对容器壁的压力分布规律,并利用三维等效弹簧元模型分析了容器壁与内部连续介质共同响应的动力特性。数值算例表明:与常用的连续介质有限元模型相比,等效弹簧元模型的计算效率和精度更高。在容器结构与内部连续介质共同响应动力分析中,等效弹簧元体系与工程中常用的附加质量法相比,不光有更高的计算效率,而且能更正确地反映内部连续介质刚度对共同响应动力特性的影响。等效弹簧元在工程应用分析中具有良好的适应性。Abstract: A method to derive the equivalent spring elements for the analysis of a two or a three-dimensional continuum is studied, and it is used in the static and dynamic analysis of the interaction in a vessel structure and its storages. At first, the theories of the equivalent spring elements to the two or three dimensional continuum are given, based on the principle of equval stiffness. Secondly, the two dimensional equivalent spring elements (ESE-2D) are used in the analysis of the pressure distribution in the vessel structure, and the three dimensional equivalent spring elements (ESE-3D) are used in the dynamic interaction of the vessel structure and its storages. The numerical tests show that the proposed ESE method can provide more efficient and higher precise computational models than the traditional finite element method for a continuum. Comparing with the added mass method, the ESE method can calculate not only more efficiently, but also more correctly in the analysis of the dynamic interaction in a vessel structure and its storages. The proposed equivalent-spring-elements method can be used widely to the mechanics analysis of engineering problems.