摘要
大跨空间网壳为缺陷敏感性结构,地震作用下其动力稳定性能更加突出。为得到大跨空间结构动力失稳的一般规律,本文从结构的整体性能出发,将地震作用转化为可以定量分析的函数形式,运用有限元理论,推导出结构动力失稳区域的微分方程,求解得到各种情况下结构的动力失稳区域,在这些区域内,即使动力荷载的幅值远远小于结构的静力失稳临界值,结构也很容易发生失稳现象;将动力失稳准则中的B-R准则和时间冻结法相结合,运用到网壳结构的动力失稳判别中,当施加在结构上的荷载工况位于动力失稳区域之内时,结构的最大位移量随着时间的增加不断加大,运动趋势整体是发散的;而当荷载工况位于动力失稳区域以外时,结构最大位移点的位移量随着时间增加具有衰减的趋势,即结构整体是稳定的。
Large-span space latticed shell is imperfection sensitivity structure, dynamic stability is more prominent under earthquake action. In order to obtain the general roles of dynamic stability, considering integral performance, seismic load transformed into function form of quantitative analysis, the theory of dynamic stability binding finite element, derived differential equation for dynamic stability region, solving the equation, dynamic instability region was obtained, even the amplitude of dynamic load is far less than the critical value of static instability,the structure liables to unstable phenomenon;the discrimination of dynamic stability using B-R criterion and time-frozen method,loads on supporting structure in dynamic stability region, maximum displacement of structure constantly gradually widens with time increasing, movement tendency is divergent; load ease beyond dynamic stability region, maximum displacement gradually reduces with time increasing, integral structure is stable.
出处
《四川建筑科学研究》
2013年第4期213-217,共5页
Sichuan Building Science
基金
河南省科技攻关重点项目(112102210361)
关键词
网壳结构
动力稳定性
失稳区域
失稳准则
latticed shell structure
dynamic stability
instability region
instability criterion
