Calculation, simulation and measurement for volume deformation of the airship with orthotropic material

The endurance of stratospheric airships is strongly affected by hull volume deformation. Conventional assumptions of rigidity and material isotropy are inadequate for accurate performance evaluation. Here, an integrated approach combining theoretical, numerical, and optical methods is presented to analyze volume deformation. Three theoretical predicting models (i.e., the constant length method, normal area method and elementary deformation method) were established and the orthotropic constitutive model of material is derived to describe deformation under overpressure. A finite element membrane model of a scaled airship is then simulated in ABAQUS, followed by non-contact 3D reconstruction using the V-STARS photogrammetric system. Based on a quantitative comparison, the constant length method yields a relatively smaller error in the calculated volume deformation. The experiment results confirm the constraining effect of locally reinforced welds. The study also shows that static analysis based on small-deflection plate theory underestimates stress by 9.43% due to omitted dynamic iteration, highlighting the need for dynamic algorithms to improve accuracy. For a full-scale airship at 2,000 Pa, volume deformation is predicted to be 2.49–3.18%. This work provides a predictive tool for structural design and leakage assessment, supporting optimized pressure control for long-endurance airships.