考虑焊缝影响的膜结构优化裁剪研究  

An optimum cutting pattern generation of membrane structures considering weld seams

作　　者：杨燕 卿强 龚景海[1] 庞妍 YANG Yan;QING Qiang;GONG Jinghai;PANG Yan(School of Naval Architecture,Ocean&Civil Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]上海交通大学船舶海洋与建筑工程学院,上海200240

出　　处：《建筑结构学报》2022年第9期286-293,共8页Journal of Building Structures

基　　金：国家自然科学基金项目(51978395)。

摘　　要：膜结构的真实应力状态对于荷载分析至关重要,然而荷载分析通常在与设计应力相对应的找形形态上进行,这样可能导致无法发现潜在的结构隐患。提出了一种考虑焊缝影响的膜结构优化裁剪及组装分析的方法。该方法通过将二维单元的节点坐标作为关键点,基于初始裁剪膜片迭代进行几何非线性有限元分析得到优化裁剪膜片,并通过膜片组装和平衡分析得到真实应力状态使最终形状最接近设计形状。在裁剪和组装平衡分析中将焊缝模拟为索单元来考虑焊缝长度方向的影响,通过修正膜单元的纬向模量来考虑焊缝宽度方向的影响。通过三个经典算例(中国帽模型、充气球模型、鞍型模型),分别进行了裁剪过程中是否考虑焊缝影响的对比分析,考虑焊缝得到的组装形态与设计形状的偏差分别降低了31.7%、96.4%、46.2%,证明了该方法可以保证实际组装形态的形状更接近设计形状。The actual stress distribution of membrane structures is of great significance for load analysis. Nevertheless, load analysis is usually based on form-found shape corresponding to design stress, which may lead to failure in detecting potential structural hazards. Therefore, a method of optimum cutting pattern generation and assembly analysis of membrane structures was proposed considering the effect of weld seams. Taking coordinates of 2 D elements as key variables, a geometrically nonlinear finite element analysis was performed based on the initial cutting pattern iteratively to generate the optimum cutting pattern, and then the assembly of cutting patterns and equilibrium analysis were carried out to obtain the actual stress distribution with the final shape closest to design shape. In cutting analysis and equilibrium analysis, the weld was simulated as a cable element to consider the influence of the length of weld, and the weld modulus of membrane elements were modified to consider the influence of the width of weld. Through three classic examples, i.e., Chinese hat model, balloon model, saddle model, the comparative analysis of whether the influence of weld seam is considered in the cutting process was carried out respectively. The deviation between assembly shape considering the weld seam and designed shape are reduced 31.7%, 96.4% and 46.2%, respectively, which proves that the method can ensure the actual assembled shape is closer to the designed shape.

关 键 词：膜结构 焊缝 裁剪分析 组装分析 真实应力分布 

分 类 号：TU358[建筑科学—结构工程]