格子状索支撑铝合金网壳结构整体稳定性能研究

Compared to the steel latticed shells, aluminum alloy latticed shells have the advantages of nonmagnetic, corrosion resistance, maintenance free, recoverable, light mass and convenient construction. The joints and stability behaviours of aluminum alloy latticed shells are different from those of steel latticed shells, because of the differences of material properties and welding performances between steel and aluminum. Thus, deep investigation is essential to be conducted to determine whether it is possible to introduce the pre-tensioned cables to aluminum alloy latticed shells, though this method has been proved to be available in steel latticed shells. This project aims to investigate the behaviour of two-way cable-stiffened aluminum alloy latticed shells, which can be formed by introducing pre-tensioned cables to aluminum alloy latticed shells. The research starts from the investigation on the behaviour of aluminum alloy gusset joints linked with four latticed shell members, in order to exploring the force-transferring mechanism and proposing the stiffness model of the joint. By introducing the stiffness model to the two-way cable-stiffened aluminum alloy latticed shells, the effects of cable layouts, cable diameters, pretension in cables, grid sizes, rise-span ratios, and load distributions on the stability behaviours can be obtained. The research results are beneficial to improving the stability behaviours of aluminum alloy, and meaningful when extending the cable-stiffened steel latticed shells to cable-stiffened aluminum alloy latticed shells. In addition, theoretical base can be provided by this research when adopting this new structural system in practical engineering.

与钢网壳相比，铝合金网壳具有无磁、耐腐蚀、免维护、可回收、轻量易于施工等优点。由于铝合金的材料特性和焊接性能均不同于钢材，因此铝合金网壳和钢网壳的节点形式和稳定性能均不相同，能否像钢网壳一样通过引入高强索提升结构稳定性能尚需进一步研究。本项目拟对在铝合金网壳中引入预张力索形成的格子状索支撑铝合金网壳结构展开研究，从格子状索支撑铝合金网壳中采用的仅连接四根杆件的铝合金板式节点入手，阐明这类板式节点的传力机制，明确其刚度特性并提出其刚度模型。将节点刚度引入格子状索支撑铝合金网壳整体结构分析模型中，明确高强拉索的优化配置方法，研究拉索直径、预张力、网格尺寸、网壳矢跨比、荷载分布等因素对这类结构承载能力的影响。研究成果有利于改善铝合金网壳的稳定性能，是将索支撑钢网壳结构体系向铝合金结构的有益推广，可为这类新型结构的应用提供理论基础。

铝合金网壳结构具有自重轻、外观美、性能好等优点。本项目以配置拉索的索支撑铝合金网壳结构为研究对象，从设置四根杆件的新型铝合金板式节点性能研究入手，考察了其在弯矩、剪力、轴力单独作用和联合作用下的刚度特性和承载能力，明确了其破坏模式。开展了影响铝合金板式节点性能的数值分析，量化了连接螺栓数量、预紧力、杆件截面高度、连接板尺寸等不同参数对节点性能的影响。在此基础上，将铝合金板式节点的刚度模型引入索支撑铝合金网壳整体结构的稳定性分析之中，验证了索支撑铝合金网壳结构工程应用的可行性，开展了索支撑铝合金网壳结构的最优形态研究，分析了不同拉索布置方式下索支撑铝合金网壳结构的承载能力，明确了不同因素对索支撑铝合金网壳结构整体稳定性能的影响。