单层球面网壳在多维地震作用下的随机响应分析

RANDOM RESPONSE ANALYSIS OF SINGLE-LAYER SPHERICAL LATTICE SHELLS UNDER MULTIPLE EARTHQUAKE EXCITATIONS

采用课题组推导的多维虚拟激励理论方法及自编计算机程序 ,对常用 K6型单层球面网壳多维地震反应规律进行了系统研究。论文首先对功率谱计算时的参数取法进行了讨论 ,然后对单层球面网壳进行了大量多维与单维响应对比分析 ,考虑了矢跨比、荷载、跨度等主要结构参数影响 ,给出了主肋、环杆、斜杆在不同参数下多维与单维地震反应对比规律及数值范围。分析结果表明 ,网壳大量主要受力杆件三维地震内力远远大于单维地震内力 ,得出在网壳抗震设计中必须要进行三维地震作用分析的结论。

Using the multi dimensional pseudo excitation method and the computer program developed by the authors, a random response analysis of single layer spherical lattice shells subjected to 3 dimensional earthquake excitations is presented in this paper. First, the parameters used for the calculation of the power spectra are suggested. Then, a large number of random analyses are performed for a K6 type single layer spherical lattice shell, and a comparison is made between the responses of single and multiple earthquake excitations. The effects of structural parameters (rise to span ratio, load intensity, span of the structure, etc.) are also investigated. It is found that the seismic forces for main members of the structure under multiple earthquake excitations are much greater than those under single earthquake excitation. It is therefore concluded that 3 dimensional earthquake excitations have to be taken into account in the seismic design of lattice shells. The results obtained in this paper can provide a valuable reference for practical design of lattice shells.