Effect of prestress on the impact performance of a fully clamped metallic beam: Analytical modeling and numerical simulation

• Effect of prestress on impact performance of fully-clamped metallic beam is investigated using a combined analytical and numerical approach. • A coupled double-solver computational framework is developed to incorporate prestress effect. • Impact performance of prestressed beam is predicted analytically using simplified string-hinge model. • Contributions of bending moment and membrane tension to energy absorption of impacted beam are quantitatively delineated. • Springback of prestressed metallic beams is revealed and predicted, enabling a precise assessment of such protective structures. Metallic protective structures (e.g., beams and plates) are widely used against impact and blast loadings. Their precise dynamic responses are critical for design and service, especially when unintended preloading or prestress caused by accidental deformation is present. In this study, the effects of prestress on the structural deformation and springback behaviors of a fully clamped metallic beam subjected to a subsequent impact load are systematically investigated. A combined research approach, consisting of analytical modeling constructed by a simplified string-hinge model (SSHM) that accounts for the roles of structural hinge and string components as well as double-solver coupling numerical simulation incorporating implicit and explicit solvers simultaneously, is employed, which is validated against existing experimental results. The influence of material strain hardening is considered. The presence of prestress can improve the impact resistance of a beam by reducing its peak deflection and increasing the structural springback of the beam, owing mainly to altered beam geometries and, initially, the stress state as the beam is deformed. Using the analytical modeling of the SSHM, the roles of the components of the hinge and string under various loading scenarios are subsequently delineated, particularly in terms of the development process of the mechanical performance of each component within the out-of-plane deformation and springback stages. During the deformation process of the impacted target, the roles of the bending moment and membrane force vary with increasing midspan deflection. These roles also change when the pretension intensity is increased.