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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300,500,800Pa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.
Due to the large volume of stratospheric airships and the small curvature of the surface of the catamaran, local stress concentration on the skins can easily lead to over-deformation and rapid damage to the skin of the airship. Based on the gradient pressure conditions , The theoretical calculation model of hoop and axial stress under the actual working condition of the airship boat bladders under the pressure difference between inside and outside is established and the Von Mises strength criterion of the aerodynamic stress analysis of the airship is established. The ABAQUS finite element software The circumferential Von Mises stresses at each point under the overpressure of 300, 500 and 800 Pa, respectively.The simulation results are consistent with those of the theoretical model, and the circumferential Von Mises stresses of the airship are increased with the increase of pressure gradient While the Von Mises stress in the axial direction is determined by the circumferential Von Mises stress and the local latitude and longitude curvature of the skin, and the Von Mises stress in both directions is positively correlated with the magnitude of overpressure load. Fundamentals of skin overpressure stress assessment and strength calculation are provided.