Frictional Analysis Of Cable Sliding And Coordinate Form-finding Of Cable-Membrane-strut By Vector Form Intrinsic Finite Element Method

Cable-membrane-strut structure is a new type of spatial structures. Unlike traditional structures made of rigid members, cable-membrane-strut structures get the stiffness by pre-stressed, during which factors like loss of pre-stress at frictional joints, the interact of structure members, tension sequence, all influence the geometric shape and pre-stress in the structure. Due to the large deformation of structure and nonlinear boundary conditions, it is difficult to deal with these problems by means of conventional finite element method.However, the theory of vector form intrinsic finite element method (VFIFE) does not need to derive stiffness matrixes in structures, so it avoids the difficulty of solving matrix equations with ill conditions, proved to be a suitable solution for the highly nonlinear analysis. It’s an explicit structural dynamic analysis algorithm first proposed by Ting. In.this method, the configuration of the structure is represented by a set of particle system instead of continuous mathematic body. The equation of motion of each particle is formulated by Newton’s second law.In this paper, the VFIFE is employed in the construction analysis of cable-membrane-strut structures. First, VFIFE was used to carry out the accurate analysis of the frictional contact force at joints, during construction and in service. And contact force between the cable and the joint was computed in a linear spring-damp system by discrete element method. Two numerical examples were developed by MATLAB, whose results show the feasibility of this analysis method. Then the whole construction process of cable dome with two loops in each layer was simulated by this method. The reasonable tension of loop cable in each phase reveals the superiority of this structure and its convenience during construction. Finally, the basic equations of triangular membrane element were derived, based on which the inflation process of an air bag was programmed. Then this element was applied in the coordinate form-finding of cable-membrane-strut structure. Compared with the cooperative analysis, the non-cooperative analysis leads to a negative impact on the geometry shape and the mechanical performance of the structure.Special features of the VFIFE make it an effective method in the analysis of cable membrane structures. At the end of the thesis, some conclusions were summarized and new research direction was proposed simultaneously.