互承式空间网格结构找形方法研究

Reciprocal spatial grid structure is a truss structure with mutually lapping bars and simple connection, which is full of rhythm beauty. It is the chief problem in reciprocal spatial grid structural design to find a proper structural configuration that can both satisfy mutually supporting relationship and architectural shape because of the limit of lapping relationship. Bar lapping factor is proposed to realize the mathematical description of lapping status and the lapping process of connection is realized numerically by bisection method. A form-finding method is put forward based on simulating the real building process. The method lifts the nodes of reciprocal grid by a fixed order until all connections satisfy the target bar lapping factor, realizing the form-finding by iterations. Numerical examples show that computing efficiency of proposed method is superior to those based on structural optimization algorithm. Bar lapping factor, rotation angle and grid density are the main influential parameters of reciprocal structural shape. Adjusting these parameters can make structural shape close to the architectural target and realize the form-finding of structures effectively.