充气式张弦穹顶结构静力性能与稳定性研究

Research on static behavior and stability of Tensairity dome

基于Tensairity结构概念设计了跨度80 m的充气式张弦穹顶结构,建立了精细化的有限元模型,实现了零状态、初始态和荷载态的全过程数值模拟,分析了结构在不同工况下的静力性能和稳定性。研究表明:该结构体系具有良好的静力性能和稳定性,内压在1～4 kPa范围内即可保证充气气囊对刚性构件的支撑作用;整体结构没有出现明显的弹性失稳问题,导致结构失效的主要原因是构件的材料破坏和膜材的应力松弛;当内压较低时,结构因上层膜面松弛而失效;当内压较高时,结构因刚性上弦大范围进入塑性状态而破坏。自振特性分析表明,该结构的整体刚性较大,但绕中心轴的抗扭刚度较为薄弱。

In this paper,based on the Tensairity structural concept,a Tensairity dome with a span of 80m was designed.A refined finite element model was built for the numerical simulation of the zero state,initial state and load state.The static behavior and stability of the dome under several load cases were analyzed.The results show that the structure system has good static performance and stability.An internal pressure of 1-4kPa can ensure that the cushion effectively supports the overall structure against stability problems.The overall structure does not have obvious geometric stability problems,and the main causes of structural failure are material destruction and membrane slack.If the internal pressure is too low,the structure fails due to slacking in the upper membrane of the cushion.If the internal pressure is too high,the structure fails as a great number of rigid upper chords yield.The structure has a large overall stiffness,but the torsional stiffness around the central axis is relatively weak.