Wrinkling And Collision-contact Analysis Of Membrane Structures Based On VFIFE

Membrane structures are widely used increasingly as a kind of facile structure. Membrane structures get stiffness by prestressed totally, so analysis of membrane structures involves many nonlinear problems such as large deformation, large rotation and mechanism movement. Due to mechanism movement, membrane torn and collision, it’s easy to appear singular stiffness matrix or not convergent iteration if using traditional finite element method. As a new analysis method of membrane structures, Vector Form Intrinsic Finite Element (VFIFE) uses point value to describe members’ spatial location and time history, not necessary to calculate stiffness matrix, which can overcome the drawbacks of traditional methods. WIFE uses Newton’s equation of motion and explicit solution, which can well solve mechanical problems such as contact, collision, fracture, collapse, etc.This thesis analyzes membrane structures based on WIFE. The studies in this thesis include wrinkling analysis and collision-contact simulation of membrane structures. Analysis methods of membrane structures are not perfect based on WIFE nowadays. For example, anisotropy of membrane is ignored in load calculation and wrinkling analysis; friction is ignored in contact and collision simulation; collision detection criterion is not perfect; etc. This thesis researches these problems based on existing literature in order to make VFBFE improve further. The studies in the thesis mainly includes:(1) deriving the constitutive matrix of anisotropic membrane structures applied to triangular membrane element of WIFE, coding a computer program for load calculation of anisotropic membrane structures based on WIFE;(2) making the main stress-strain criterion and the corrected constitutive matrix method applied to WIFE, deriving the corrected constitutive matrix of wrinkled anisotropic membrane structures, and proposing the more reasonable calculation method of angle between main and eccentric coordinate;(3)deriving the methods and formulas of edge-edge criterion of membrane structures, which makes the collision detection criterions of membrane structures further perfect together with point-triangle criterion of existing literature, and coding a program to verify their correctness;(4)using corrected geometric coordinates of nodes method to process collision response of membrane structures, which includes repulsive force and friction, deriving relational formulas and coding a program to calculate examples.This thesis embodies many advantages of VFIFE on analysis of membrane structures, improves relational theory, and makes VFIFE be applied for actual projects earlier. At last, it proposes research direction against inadequate of studies of VFIFE on analysis of membrane structures.