ETFE双层气枕计算分析及比较

基于U.L.格式的非线性有限单元法,编制了ETFE双层气枕找形分析、受荷分析的计算程序,并选取圆形、正六边形、正三角形、菱形及正方形5种工程中常用的气枕作为计算模型进行对比分析.在找形分析时,将矢高、内压和初始张力作为控制参数进行计算并依次给出了三者之间的相互关系.在受荷分析时,考虑6种给定的荷载工况,计算了ETFE气枕体积、内压的变动以及膜面的主应力.数值计算结果表明,形状与圆形相差较大的双层气枕其力学性能变化明显.在气枕的体积和内压变化不大时,可直接根据气枕上层膜面的主应力判定气枕的工作状态.

Structural analysis and comparison for double-layer ETFE cushions

Based on updated Lagrangian formulations,the nonlinear finite element method is employed to develop a program for form-finding analysis and stress analysis of double-layer ethylene tetra fluoro ethylene(ETFE) cushion.Five types of cushions with different shapes are selected as the analytic models.The rise,the internal pressure and the initial stress are taken as the parameters in form-finding analysis and the relationships among these parameters are given by calculation.In stress analysis,the changes of the volumes and the internal pressure,and the principle stresses of the ETFE cushions are calculated in which six load cases are considered.According to the numerical results,the mechanical properties of the different cushions are presented.The working state of ETFE cushions can be decided by the principle stress of up-layer membrane on condition that the internal pressure change is less than 5%.