均布荷载作用下单层球面网壳的弹塑性失稳模式研究

Elasto-Plastic Instability Mode of Single-Layer Latticed Domes under Uniform Load

为揭示单层球面网壳结构在静力均布荷载作用下的失稳模式与失效机理,预测结构可能发生的破坏模式和承载能力,基于双重非线性全过程分析理论,采用ANSYS软件对典型球面网壳结构开展稳定性参数分析,系统考察结构的荷载-位移全过程曲线、塑性发展分布、屈曲模态等特征响应。并以典型算例为代表,从宏观和微观两个方面诠释了单层球面网壳结构可能发生的3种失稳模式:弹性失稳、弹塑性提前失稳、弹塑性失稳。指出弹塑性提前失稳是由于结构强度破坏诱发的一类承载力偏低的失稳模式,为提高结构安全性,在网壳稳定性设计阶段中应避免出现此类失稳模式。

In order to reveal the instability mode and failure mechanism of single-layer latticed dome under static uniform load, and to evaluate the possible failure modes and load bearing capacity of the structures, based on the double nonlinear complete load-deflection analysis theory, the stability parameter analysis of typical latticed domes are carried out by ANSYS software. The characteristic response of the structure such as the complete load-deflection curve, the development of plasticity and buckling modes are systematically studied. And for the typical example, three possible failure modes of reticulated shell structures~ elastic instability, early elasto-plastic instability, elasto-plastic instability are interpreted from both macro and micro aspects. It is pointed out that the early elasto-plastic instability induced by strength damage is a kind of structure instability mode of which the corresponding bearing capacity is relatively low. In the stability design stage, such instability mode of reticulated shell should be avoided to improve the structural safety.