Wrinkling And Dynamic Loading Analysis Of Tensioned Membrane Structures

In the recent years, the fundamental theories of membrane structures have been understood, while there are still some problems needed to be solved, such as Wrinkling Analysis, Dynamic Analysis and Wind-Structure Interaction Analysis. The first two problems are focused in this dissertation.As the basis of the loading and wrinkling analysis, the definitions of Kirchhoff Stress in the original reference configurations and Cauchy Stress in the updated reference configurations are studied. According to the relationship between these two stresses the finite element formulas of plan membrane unit and cable unit are developed. The relationship between the Green Strain and Almansi Strain is also presented. Further more the relationship of two constitutive matrixes is developed.There are a few criteria for the wrinkling judgment, such as Principal Stress Criterion, Principal Strain Criterion and Principal Stress-Strain Criterion. After carefully studying, Principal Stress and Strain Criterion is believed to be the most appropriate one for membrane structures wrinkling judgment. A few approaches for wrinkling analysis, such as, Tension Field Theory, Variable Poisson's Ratio Method, Modified Deformation Tensor Method, Modified Constitutive Relationship Method and Bifurcation Buckling Theory, are introduced. After the Modified Constitutive Relationship Method is improved, it is used in the Membrane Structure Wrinkling analysis.The process of the Membrane Structure Wrinkling Analysis is given and attached to self-owned Membrane Structure Analysis Software. The validated program is applied to analyze the wrinkling of membrane structures under the static loading.The dynamic characteristics analysis program of membrane structures is programmed by Subspace Iteration Method. Natural frequencies and modes of three typical kinds of saddle shaped membrane structures are analyzed.Dynamic Analysis equations are developed in which Newmark method, Newton-Raphson Iteration method and Modified Constitutive Relationship Method are applied, geometrical nonlinearity and material nonlinearity are considered at the same time. The membrane structure dynamic analysis is programmed according to the equations. And the basic performance of a membrane structure under dynamic loading is presented.Three typical kinds of membrane structure with different pretension, dimension under different harmony loading are analyzed. The relationships between the structure response and harmony load frequency, pretension force, structural dimension are given. And the results of these three kinds of structures are compared.The fluctuating wind speed with Davenport Spectrum is generated, and the pressure coefficients of structure are gotten by using Computational Fluid Dynamics method. The Membrane Structures under the wind load are analyzed. And the performance of Membrane Structures under the dynamic wind load and the influence of membrane wrinkling are discussed. The dynamic analysis of an engineering project under wind loading is also presented.