Research On Dynamic Responses Of Corrugated Hybrid Sandwich Panels Under Air Blast Loading

Sandwich structures are applied to a wide variety of transportation media, including airplane, motor car and marine, due to their light weight, high strength and excellent blast performance. The performance of ship protectivestructure directly affects the vitality of the warship. For the corrugated hybrid sandwich panel, which is a new defensive structure, it is required to exactly evaluate its blast performance. Therefore, in the case of air blast loading as well as combined effect of blast and fragment loading, it is of great importance to study the mechanical behavior of sandwich panel. The main highlights in this work are as follows:(1) The investigations on the dynamic response of corrugated hybrid sandwich panels under air blast loading were conducted using the finite analysis code Autodyn. It turned out that the numerical results agreed well with the experimental data. Based on the validations, the effects of stand-off distance and filling strategy on the sandwich panels were analyzed in terms of pressure on coupling face, plastic deflection and velocity of face-sheets and energy absorption characteristics. The results showed that the fully filling configuration contributed to the optimum blast resistance, followed by upper space filling, lower space filling and empty configuration, while the total energy absorption went exactly the opposite way.(2) Taking the graded corrugated and graded corrugated hybrid sandwich panels as study object, the simulations on dynamic response under air blast loading were also implemented in Autodyn, separately. The effects of core arrangements on response modes and energy dissipation in every part of graded corrugated panels were analyzed, resulting in a core configuration with that the sandwich panels can perform optimal blast resistance performance. Furthermore, the influence of filling configuration on the response pattern, plastic deflection and energy absorption in every component of graded hybrid corrugated sandwich panels. The results revealed that the deflection on bottom face sheet of sandwich panel was the minimum, in which the first core layer was filled with foam.(3) Moreover, for hybrid corrugated sandwich panel subjected to combined effects of blast and fragment loading, the numerical studies on the dynamic response were analyzed in finite analysis code LS-DYNA. The deformation/failure pattern under various loading conditions were interpreted. The comparison of anti combined loadings performance to three equivalent structures were made. In addition, the effects of thickness configuration of face sheets on resistance performance were analyzed. The analysis demonstrated that the sandwich panels with fully filling configuration possessed the best damage resistance, followed by upper space filling, and that with lower space filling configuration had the worst. Finally, the energy absorption characteristics of corrugated sandwich panels were discussed.The research work of this dissertation provides a useful reference for using corrugated hybrid sandwich plate in warship defensive structures.