正交异性膜材大变形行为的有限质点法求解

LARGE DEFORMATION ANALYSIS OF ORTHOTROPIC MEMBRANES USING THE FINITE PARTICLE METHOD

建筑薄膜具有正交异性和拉伸非线性的力学特性,其本构关系的表征和大变形行为的描述都较为复杂,具有很强的几何、材料双重非线性特征。有限质点法是一种新颖的结构数值分析方法,它将传统分析力学方法中复杂的函数连续体模型用清晰的离散质点物理模型取代,通过质点的运动描述结构的行为。该文根据途径单元的基本概念直接在质点内力计算过程中引入不同的膜材本构,将有限质点法拓展应用于正交异性薄膜结构的几何与材料非线性大变形分析。为了准确表征膜材力学特性,根据复合材料本构理论分别建立了适用于有限质点法的正交异性膜材的线性与非线性拉伸本构模型,并通过若干算例探讨了该文方法和程序的适用性和正确性。

Due to the orthotropic and tensile nonlinear characteristics of thin structural membranes,the constitutive relation and large deformation behavior of these materials are complicated,as it always has strong geometry and material nonlinearity.The finite particle method(FPM)is a novel structural numerical method,which models the analyzed domain by a set of discretized particles instead of a mathematical continuous body in those traditional methods based on analytical mechanics.It describes structural behaviors by analyzing particles movement.With the concept of path unit,it is convenient to introduce various constitutive laws of membranes in the evaluation of internal forces.This paper explores the possibility of the proposed method being applied in the large deformation analysis of membrane structures exhibiting the geometric and material nonlinearity.According to the constitutive theory of composite materials,two material models(i.e.linear and nonlinear orthotropic models)are developed and implemented in the program.Numerical examples are presented to demonstrate the validity and applicability of this method.