考虑杆件失稳影响的网壳结构稳定性研究

为了解和掌握杆件失稳对网壳稳定性的影响,指出判别网壳结构杆件失稳的关键问题并提出杆件失稳的判别方法。采用有限元软件ANSYS及自编的前后处理程序对已有网壳试验进行对比分析,得到模型结构的全过程响应、杆件失稳的判断结果和杆件失稳对结构的影响,分析结果符合已有试验结果。并以Kiewitt8型球面网壳为例,分析网壳结构杆件失稳特征及在网壳结构中的传播规律。同时,在考虑杆件稳定性的基础上,考察材料非线性、初始几何缺陷以及杆件挠曲二阶效应和挠曲失稳对杆件稳定性和网壳稳定性的影响规律。结果表明提出的方法可以有效地判断网壳结构杆件的稳定性,杆件失稳及其传播将直接影响结构稳定性。

Study on stability of reticulated shell structures considering the influence of member buckling

In order to understand the influence of member buckling on the stability of reticulated shells,a key issue on how to distinguish member buckling for reticulated shell structures was pointed out,and methods for discriminating member buckling was proposed.A reticulated dome model tested was analyzed and compared by using the finite element software ANSYS.The total response,judgment results of member buckling and the influence of member buckling on the structure were obtained.The analyses results are in good agreement with the test.Using a Kiewitt8 dome as an example,the buckling characteristics and propagation pattern of member buckling were studied.Meanwhile,taking the member buckling into consideration,the effect of material nonlinearity,initial geometric imperfection,and bending second-order effect and bending buckling of members on the stability of the members and the reticulated shell structures were investigated.The results show that the proposed methods can discriminate the member buckling for reticulated shells effectively;the member buckling and its propagation can affect the stability of the structure directly.