非对称荷载作用下K6型单层球面网壳结构的动力稳定性  

Dynamic stability of K6 single-layer spherical reticulated shells under asymmetric loads

作　　者：周锟[1] 葛文星 王秀丽[1] 南宁 ZHOU Kun;GE Wen-xing;WANG Xiu-li;NAN Ning(College of Civil Engineering,Lanzhou University of Technology,Lanzhou 730050,China)

机构地区：[1]兰州理工大学土木工程学院,甘肃兰州730050

出　　处：《空间结构》2021年第3期17-24,31,共9页Spatial Structures

基　　金：甘肃省自然科学基金项目(1506RJZA092)。

摘　　要：为了研究非对称荷载作用下K6型单层球面网壳结构的动力失稳机理,采用数值模拟和试验方法,依据结构峰值加速度和节点最大位移曲线将失稳过程分为3个阶段:线性阶段、非线性阶段和失稳阶段,定义了两个关键点:临界点和失稳点.研究表明,K6型网壳结构峰值加速度-节点最大位移曲线能够很好地描述结构整体的动力失稳过程,提出用临界点作为判定结构动力失稳的依据更为保守,增大结构刚度能明显提高网壳结构的稳定性;网壳结构危险点的分布位置受荷载的作用形式、荷载的大小以及输入地震波的频谱特性等因素影响,结构在线性阶段危险点点位是相对确定的,而在非线性阶段危险点点位是不确定的.数值模拟分析结果和地震振动台实验结果能够较好地吻合,验证了数值模拟计算的正确性.In order to study the mechanism of dynamic instability of K6 single-layer spherical reticulated shells under asymmetric loads,the method combining numerical simulation and experimental demonstration is adopted.Based on the peak acceleration and maximum node displacement curves,the instability process of the single-layer spherical reticulated shell is divided into three stages:linear phase,nonlinear phase and instability phase.In addition,two key points are defined:critical point and instability point.The results show that the peak acceleration-maximum node displacement curve of the K6 single-layer spherical reticulated shell can well describe the instability process of the whole structure,and the critical point is proposed to determine the dynamic stability of the structure.The stability of reticulated shell structure can be improved obviously by increasing the structural stiffness.The distribution of danger points on reticulated shell structure is influenced by the action form of load,the magnitude of load and the spectral characteristics of input seismic wave.The danger point position of the structure is relatively certain in the linear stage,but uncertain in the nonlinear stage.The results of numerical simulation are in good agreement with those of shaking table test,which verifies the correctness of numerical simulation.

关 键 词：单层球面网壳结构 非对称荷载 动力稳定性 倒塌机理 

分 类 号：TU393.3[建筑科学—结构工程]