一种球面网壳动力失效的联合预测方法

Combined method for predicting the dynamic failure of single-layer latticed dome

以地震作用下精细化有限元分析的单层球面网壳的动力失稳破坏模式为基础、结合细胞自动机(CA)方法,发展了一套单层网壳动力失稳破坏模式和失效荷载的联合预测方法。首先,对基础单层球面网壳进行了简谐荷载作用下全荷载域动力时程有限元分析(FEA),并时时提取各级动荷载幅值下所有节点的位移值及单元的应变能密度。之后,用建立的联合方法预测了其它同类网壳的动力失稳破坏模式及失效荷载,并与相应FEA计算结果进行了分析比较。结果表明,所提出的联合方法,在一定程度上能基于一个单层球面网壳的动力失稳破坏模式和失效荷载预测其它不同跨度、不同矢跨比、不同杆件截面尺寸的单层球面网壳的动力失稳破坏模式及失效荷载。因此,结合FEA数值模拟,实现了CA方法在单层球面网壳动力失稳破坏模式和失效荷载预测中的应用。

A combined method was developed which can predict the dynamic instability modes and failure load of a single-layer latticed dome according to the seismic instability modes and failure load of a base dome. Firstly, the finite element models of single-layer latticed domes were built to calculate their full time-range seismic responses inclusive of the nodal displacements and the strain energy density of all the elements corresponding to each load step at individual seismic intensities. Then, the combined method was applied to predict both the dynamic instability modes and failure load of unseen single-layer latticed domes based on the dynamic instability modes and failure load of the base domes. The predicted results were compared with the corresponding fine finite element analysis （FEA） results of the unseen domes. To an extent, the developing combined method could be used in predicting the dynamic instability modes and failure load of the similar kinds of single-layer latticed domes with different spans, different rise-span ratios and different member section sizes. Hence, the study explores the application of the method of cell automat （CA） in the analysis and prediction of the instability modes and failure load of single-layer latticed domes, combining with the existing fine FEA numerical data of the domes.