气枕式充气膜结构形态与受力分析

为解决气枕式充气膜结构在荷载作用下的变形问题,采用非线性有限元方法对气枕式充气膜结构进行形态分析的基本方法.气枕式充气膜结构的形态分析分为两个阶段:即找形分析与找态分析,由此可得到满足相应要求的几何模型与应力状态.假设密封气枕内质量一定的气体满足理想气体状态方程,在荷载作用下,内压随着体积的变化而变化.给出在一定压力作用下半球状气枕的验证算例并与材料力学中给出的理论解进行比较;基于该方法,另对气枕式充气膜结构在不同外荷载作用下的受力状态进行分析并给出相应的算例,计算结果表明采用理想气体状态方程可以模拟在外部荷载作用下气枕的变形、应力状态以及内压变化情况,且是合理有效的并具有较高的准确性.

Form-state and loading analyses of air-rated cushion membrane structures

To analyze the deformation of the air-inflated cushion membrane structures under different load conditions,the nonlinear element method was adopted. By dividing the form-state finding process into a two-stage numerical simulation procedure comprising of the form-finding step and the state-finding step,the geometric model and the stress state under working load condition were determined. The key feature of the cushion is the preservation of the mass of the gas,which is supposed to satisfy the perfect gas state function in an enclosed surface. So based on the model from the form-state calculation process,the changes in the air pressure resulting from changes of the cushion volume under the application of external forces were evaluated and taken into consideration. The calculation result of a numerical example was given to prove the correctness of the form-state finding and load analysis method compared with the theoretical values of advanced material mechanics. A numerical example under different external load conditions using the theory presented was provided as well. By adopting the perfect gas state function to evaluate the deformation,stress distribution and internal pressure of cushion under different external load conditions,the valid and accuratre result can be obtained.