空气对预应力薄膜结构模态的影响

摘要

The influence of air on pre‐stressed membrane struture was revealed in order to give an anlysis method for modal behavior test and calibration of membrane structure . First , pre‐stress of membrane structure was introduced by appling initial stress directly and adding temperature load ,respectively ,and then their effects on the modal behavior were analyzed .Second ,the effect of air on pre‐stressed membrane structure was studied based on the potential fluid theory of fluid‐structure interaction .Finally ,modal behavior test and identifiaction on ETFE film reflect‐array were taken using biaxial extension test set‐up and non‐contact laser vibration system ,and the numerical simulation method was verified .The test results reveal that the introducing method of prestress has nothing to do with the modal behavior analysis ,while air has a significant impact on the modal behavior of pre‐stressed membrane structures ,and its impact is related to the film material and air density .%为了提供薄膜结构模态测试和校验的分析方法，揭示空气对预应力薄膜结构模态的影响，分别采用直接施加初应力和施加温度荷载的方法给薄膜结构导入预应力，并分析预应力引入方式对模态的影响。基于流固耦合势流体原理，研究空气对预应力薄膜模态的影响。利用双轴张拉装置和无接触激光测振系统对ET FE薄膜阵面进行模态实验和识别，并验证数值模拟方法。研究结果表明：预应力导入方式对模态分析无影响，空气对预应力薄膜的模态有着显著影响，其影响的大小与薄膜材料以及空气密度相关。