基于压差梯度的平流层飞艇艇囊应力计算和仿真

平流层飞艇体积庞大,艇囊表面曲率小,因而蒙皮材料的局部应力集中极易导致飞艇艇囊蒙皮发生过大变形而迅速超压损伤破坏.基于飞艇艇囊内外压力压差梯度载荷条件,建立飞艇艇囊蒙皮受内外压差真实工况下环向与轴向应力的理论计算模型,构建飞艇蒙皮应力分析的Von Mises强度准则.并采用ABAQUS有限元软件非线性仿真艇囊蒙皮分别在超压300,500,800 Pa载荷下的各点环向的Von Mises应力状况.仿真结果与理论模型计算的应力值基本保持一致,飞艇艇囊蒙皮环向Von Mises应力呈现随压差梯度增大而递增的规律,而轴向Von Mises应力大小由环向Von Mises应力、蒙皮局部经纬向曲率共同决定,且两方向的Von Mises应力均与超压载荷大小成正相关关系,为飞艇艇囊蒙皮超压应力评估和强度计算提供基础性研究.

Calculation and simulation of stratospheric airship capsule stress considering the pressure gradient

The capsule volume of stratospheric airships was usually too huge and the surface curvature of buoyancy capsule was small, so local stress concentration of airship envelope could easily lead to large transformation and cause the capsule to overpressure damage and blast quickly. Basing on the pressure gradient loading condition of the inside and outside of the airship buoyancy capsule, the theoretical calculation method of the hoop and axial stress was developed under the real overpressure load working situation, and the Von Mises stress strength criterion was proposed as well. The finite element (FEM) analysis software ABAQUS was used to simulate the hoop Von Mises stress under the different overpressure loads of 300, 500 and 800 Pa respectively. The contrastive results show the Von Mises values between the simulation and theoretical calculation are in consistent nearly, and the hoop Von Mises stress of airship capsule envelope increases with the increasing of pressure gradient, While the axial Von Mises stress of airship overpressure capsule is determined by the hoop Von Mises stress and envelope local curvature of the warp and weft directions together, moreover, the two kinds of Von Mises stress associated with the overpressure load is positively correlated at different directions, which provides the effective basis research of stress evaluation and strength calculation for the airship envelope overpressure.