基于能量的网壳结构协调抗震性能分析

Energy-Based Analysis of Anti-Seismic Performance of Latticed Shell in Coordination

为了揭示地震作用下网壳结构各局部间受力状态及该变化与结构承载能力间的关系,对有限元全荷载域动力时程分析应变能数据进行了再建模,在此基础上应用能量参数系统研究了地震作用下网壳结构各杆件内力重分布.研究结果表明,网壳结构在工作状态下各单元间能够协调、稳定地共同承担外荷载;当结构失效后,各单元间协调变形的稳定性被破坏,基于协调变形可以判断网壳结构的工作状态;在水平向动荷载作用下,单层网壳中下部指数应变能较大,径杆最大值出现在第5环,约为第1环的13倍;三向地震波作用下,中上部指数应变能较大,径杆最大值出现在第2环,约为第6环的15倍.

An analytical numerical model was rebuilt to reveal changes in local stress state in a singlelayer reticulated shell under earthquake,as well as the relationship between the changes and structural failure loads. The numerical model was rebuilt based on the strain energy from nonlinear response history analyses at increasing levels of ground motion intensity to systematically study the redistribution of seismic internal force in elements in the single-layer reticulated shell by using the strain energy parameter. The results showed that elements in a single-layer shell can bear seismic loads harmoniously and steadily in the normal working state. However,harmonious and steady characteristics were not observed in the failure state. Therefore,different stress states can be distinguished by checking the structural coordinative working capability. In addition,the strain energy in the lower parts of the single-layer reticulated shell was larger than that in other parts such as in the radial members under horizontal ground motion,the maximum value was observed in the fifth hoop,which was 13 timeslarger than that in the first hoop. The strain energy in the upper parts of the single-layer reticulated shell was larger than that in other parts such as in the radial members under 3 D ground motion; the maximum value was observed in the second hoop,which was 15 times than that in the sixth hoop.