Mechanical Analysis Method Of Membrane Structures Considering Cutting Pattern

In recent years, membrane structures have been increasingly widely used. Different from the traditional structures,'shape'and'state'are of great importance. And cutting pattern analysis is the key bringing'shape'and'state'into reality. The resulting shape from the form finding analysis is generally a three-dimensional undevelopable surface; cutting film itself gotten from cutting analysis is plane. This discrepancy influences the structure's shape and mechanical behavior, but there're few research on this problem. For this reason, it is meaningful to discuss the membrane structure analysis method considering cutting pattern.In this paper, three geodesic line generation methods-functional binding method, updated geometrical method and nonlinear finite element method have been introduced in details and programmed accordingly. And then through examples, the author makes a contract analysis. Analysis showed nonlinear finite element method is higher accurate and easier to use.This paper proposes the forming simulation method based on the nonlinear finite element theory and validates its feasibility by theoretical methods and examples. The results show that the influence of cutting pattern on the structural shape and state is in general not negligible.Taking a saddle tensioned membrane structure and a spherical inflatable membrane structure as examples, forming simulation is conducted. And then based on the results of forming simulation, considering two load cases, the author makes the mechanical analysis, taking account of the numbers and arrangements of cutting film. Through above analysis, we can get some meaningful conclusions: there's limited improvement through increasing numbers of cutting film. Cutting pattern's influence on structure's mechanical behavior could be considered for the saddle tensioned membrane structure, but ignored for the spherical inflatable membrane structure.