Research On Design Reliability Of Typical Tensioned Membrane Structyres

The traditional membrane structure design method still uses the experience of the whole factor of safety,and can not well consider the influence of uncertain factors.There are a lot of uncertainties in the mechanical properties,geometrical properties,calculation models and load variations of membrane structures.The reliability-based analysis of membrane structures has become a hot research topic in recent years.As a reliability algorithm,the first order second moment method has been widely used in other structures because of its mature theory,simple method and high efficiency.In this paper,the First order second moment and Response surface method(FOSM-RSM)is proposed by combining the advantages of the First order second moment in reliability calculation with the Response surface method to improve its fitting in the limit state function,the Algorithm is applied to calculate the reliability of membrane structure,and the research work is carried out for the reliability analysis of membrane structure.The main contents are as follows.(1)The uncertainty analysis of the basic variables of membrane structure is carried out from the four directions of material properties,geometric parameters,calculation mode and load.(2)In order to solve the problem that the limit state of membrane structures can not be expressed by the display function in the reliability analysis of membrane structures,the FOSM-RSM is proposed.Four key problems involved in the method,such as standard space transformation,stochastic finite element model of membrane structure,determination of function form and sampling point,are discussed.(3)Based on the FOSM-RSM method,the reliability of the saddle-shaped and umbrella-shaped tensioned membrane structures is analyzed.The influence of different load combination,prestress,variable load and rise-span ratio on reliability index is discussed and compared.Based on the total probability method,the partial coefficients of membrane structures are calculated and compared with the Factor of safety method stipulated in the technical specification for membrane structures(CECS 158:2015).