预测单层柱面网壳破坏模式的细胞自动机方法

Cellular automata technique for predicting failure mode of single-layer latticed cylindrical shell

摘要:

为改进网壳结构有限元数值模拟效率以及拓展数值模拟结果应用,发展了一种预测单层柱面网壳结构破坏模式的细胞自动机方法．该方法通过有限元模拟,给出了单层柱面网壳简谐地面运动下动力失稳破坏模式和TAFT地震波作用下动力强度破坏模式;然后,用归一化节点有限元位移值、以及归一化节点对数应变能密度值构成网壳两种细胞自动机状态模式;进而,建立了单层柱面网壳相似节点域的概念,并给出了相应的匹配准则;最后,以基础网壳破坏模式为依据,通过匹配基础网壳和目标网壳之间的相似节点域,预测了目标网壳失稳破坏位移模式和强度破坏对数应变能密度模式．预测结果验证了所发展的细胞自动机方法的有效性,期待成为分析网壳结构的新途径．

Abstract:

This paper develops a cellular automata (CA) technique for predicting the failure modes of single-layer latticed cylindrical shells to address computing time cost and explore computing results’ further application. Firstly, finite element analysis gives out the failure modes of the single-layer latticed cylindrical shells under harmonic loads and TAFT seismic waves. Then, two CA numerical modes are established: the dynamic instability modes of shells under harmonic ground motion, described by the normalized finite element node displacements; the strength failure mode under TAFT seismic waves, described by the logarithmic strain energy density of node domain. Moreover, the concept of node domain similarity is proposed and the corresponding criterion is established to match the node domain similarity between shells. Finally, the CA technique is formed to predict the dynamic instability modes and the strength failure modes of objective shells, based on the failure modes of base shells. The predicted results validate the CA technique, which could be a new way for analyzing shell structures.