Dynamic Deformation Model of Thin-Walled Ellipsoidal Shells under Impact Loads

To delve into the nuanced understanding of the deformation characteristics of thin-walled ellipsoidal shells under localized impact loads, a systematic and comprehensive research approach was employed, integrating both experimental exploration and simulation analysis. The experimental setup featured a lightweight pneumatic gun for conducting projectile impact experiments, with the deformation process meticulously recorded using advanced three-dimensional Digital Image Correlation (DIC) technology. This extensive study necessitated a detailed examination of the overall deformation morphologies of ellipsoidal shells, particularly under varying initial impact velocities induced by cylindrical projectiles. The outcomes of the study provided crucial insights into determining the central depression depth and the corresponding boundary positions of the long and short axes. In the simulation analysis of ellipsoidal shell impacts by projectiles, the primary focus was directed towards elucidating the intricate interplay of alterations in three curvature radii on the complex interactions affecting the ellipsoidal shell's depression depth and the long and short axes. Employing dimensional analysis, essential dimensionless independent variables governing deformation characteristics were identified, refined through parameter sensitivity analysis to eliminate less influential parameters. The resulting specific response surface function elucidates the nuanced relationships among dimensionless deformation characteristics, the three curvature radii, and velocity. Under the condition of consistent material properties and the maintenance of equivalent shrinkage ratios for projectile body size and shell thickness, a predictive formula for global deformation based on depression depth and boundary conditions was derived. This formula demonstrates commendable dimensional consistency and affords high prediction accuracy. The potential application extends to informing the engineering design of impact load protection for large-sized curved shells, holding considerable promise in enhancing structural resilience and mitigating potential risks in engineering applications. The comprehensiveness and depth of this study provide a robust foundation for future research in related fields.