直角梯形ETFE气枕塑性成形试验与数值分析

Plastic-forming Experiment and Numerical Analysis of Right Angled Trapezoid ETFE Cushions

乙烯-四氟乙烯共聚物(ETFE)薄膜材料具有良好的塑性性能,利用这一性能,ETFE气枕可以进行基于平面裁剪的塑性成形.制作了两个直角梯形ETFE气枕模型,设计了气枕充气泄气压力控制系统,对两个气枕分别进行充气成形试验和循环充气加载试验,利用激光位移计对膜面位置进行测量.试验结果表明,经过2kPa内压的塑性成形,得到的两个气枕的矢跨比分别为1/9.4和1/10.3,成形过程使ETFE薄膜材料发生强化.采用多折线各向同性强化的弹塑性材料模型模拟ETFE薄膜,通过ANSYS软件进行了气枕成形以及循环加载的数值分析,并对数值分析结果与试验结果进行了对比分析.

Plastic-forming based on plat-patterning is applicable to ethylene tetrafluoroethylene （ETFE） cushions owing to the good plasticity property of ETFE foils. Two right angled trapezoidal ETFE cushion models were designed and manufactured. Cushion forming and cyclic inflating-deflating tests of the two ETFE cushion models were carried out by employing a pressure control system. Vertical displacements on the lower surface were measured by laser displacement transducer. The results indicate that rise-to-span ratios of the two cushions are respectively 1/9.4 and 1/10.3 with 2 kPa being the maximum internal pressure of plastic-forming. In addition, the ETFE foils were strengthened during the forming process. A multi-linear elastic-plastic model withisotropic hardening in ANSYS was employed to numerical analyses of the forming and cyclic inflating-deflating processes, and the results were compared with the experimental data.