Evolution of curing residual stresses for filament‐wound egg‐shaped pressure‐resistant shells considering viscoelastic properties

Abstract The filament‐wound egg‐shaped structure offers significant performance improvements and structural advantages for deep‐sea submersibles, including enhanced pressure resistance, optimized space utilization, and improved hydrodynamic performance. However, the residual stresses generated by the curing process are an unavoidable key issue in filament winding. This study aims to investigate the thermal curing residual stresses and its resultant distortions on filament‐wound egg‐shaped pressure‐resistant shells under different structural parameters. First, the wound trajectory is determined based on the principles of differential geometry and the fourth‐order Runge–Kutta method combined with the egg‐shaped profile equation. Then, a thermo‐chemical–mechanical multi‐field coupling analysis is conducted using the Kamal autocatalytic curing kinetics model and the generalized Maxwell viscoelastic constitutive model. The curing mechanism of the egg‐shaped filament‐wound pressure structure is revealed. Finally, a comprehensive analysis is conducted on the influence of structural design parameters including shape index (SI), slip coefficient, layer thickness, and liner thickness on residual stress and deformation. The results show that the residual stress in the fiber direction increases sharply with temperature during the curing process, reaching its peak during the secondary curing stage, and gradually relaxes during the cooling phase. The stress in the polar region is complex, while it is more uniform in the non‐polar regions. Parametric analysis indicates that the residual stress and displacement of the metal liner for shape index 0.8 increase significantly by 148.02% and 125.44% compared to shape index 0.4. Highlights Consider the viscoelastic behavior of the resin in curing predictions. Outside the polar hole, the outermost wound layer shows compressive stress. In non‐polar pores, stresses in filament‐wound layers fall outward. Adjusting the slip coefficient reduces curing deformation and residual stress. Shape index, ply, and liner thickness significantly impact residual stress.