单层球面网壳动力失效全过程试验研究

Whole process test and dynamic failure analysis for single-layer spherical lattice shells

为了更加深入研究单层球面网壳的动力失效。结合一个K6型单层球面网壳振动台试验,设计出一套描述单层球面网壳强振倒塌全过程的测试方法,包括:冲击法测试结构自振特性、低频调幅加载评估损伤程度和基频简谐加载监测结构失效过程。结合数据测量结果,描绘出结构倒塌过程的变形时程,分析结构的基频、阻尼及振型,记录杆件进入塑性的顺序,探索结构损伤演化的规律及倒塌破坏的机理。最后考虑材料的损伤,进行有限元模拟,验证了模拟方法的正确性。

In order to study deeply the dynamic failure process of single-layer spherical lattice shells,combining with shaking table tests of a K6 type single-layer spherical lattice shell,a set of vibration test methods describing the whole collapses process of single-layer spherical shells under strong earthquakes was designed. It included the impact method measuring natural vibration characteristics of structures, the low frequency amplitude-modulation loading assessing structural damage level,and the fundamental frequency simple harmonic loading monitoring structural failure process.Based on the data results of measurement,the collapse process＇ s deformation history of a structure was described. The fundamental frequency,damping and modal shapes of a structure were analyzed. The order of bars of a structure to enter a plastic state was recorded. The rules of structural damage evolution and collapse failure mechanism were explored. At last,considering material damage,the whole failure process of signle-layer spherical lattice shells was simulated with the FE method. Comparing with the test results,the correctness of the simulation method was verified.