The Simulation Of Metal Honeycomb Sandwich Panel Under Thermomechanical Coupling

With the advantages of lightweight, high ratio of strength and stiffness to weight, and excellent design ability, etc the metal honeycomb sandwich structures have become one of the vital materials in aerospace, shipbuilding and other fields. However, its mechanical properties were influenced inevitably by high temperature in many engineering applications when used as heat exchanger lining, components of thermal protection system, etc. Based on this, the three-point bending properties of metal honeycomb sandwich structure under room and high temperature were carried out in this paper. The main works are as follows:First, the equivalent methods and calculation model of honeycomb sandwich structure were described, the mechanical properties of metal honeycomb sandwich structure were theoretical analyzed under the three-point bending, and the equivalent shear modulus of honeycomb cores was derived, the shear stress of honeycomb cores was analyzed.Second, with the finite element software the numerical simulation of metal honeycomb sandwich panel under three-point bending was carried, the effect of structure strength with different orientation was analyzed, and the effect of the different grid sizes on the simulation results was discussed, the metal honeycomb sandwich panel was equivalent to a common panel, and the difference of the stress state between the metal honeycomb sandwich and the common panel was analyzed.Third, through the simulation of metal honeycomb sandwich under both ends clamped and three-point bending, the effects of high temperature environment, thermal stress and elastic constants on the metal honeycomb sandwich structure were analyzed. The simulation results of metal honeycomb sandwich panel under room temperature and high temperature were compared.Finally, the optimized design of metal honeycomb sandwich structure was performed. Under the strength and stiffness satisfied, the panel thickness as the design variables, the overall weight of honeycomb sandwich panel as the objective function, the minimum weight's geometry of the metal honeycomb structure was obtained by the optimization design.The results show that the honeycomb sandwich structure which brazed by carbon steel under the three-bending experiments, the L direction specimen were 10% stronger than W direction specimen. The shear strength of honeycomb core was enhanced, and satisfied the shear strength requirements; the large deformation was the main failure mode of the structure in bending under high temperature. Plastic deformation occurred obviously in specimens, while there was no fracture happened. Under the strength and stiffness satisfied, the minimum weight's geometry of the metal honeycomb structure was obtained by the optimization design. The simulation results were well agreed with the experiment results.