Study On Preparation And Mechanical Property Of Composite Sandwich Constructions

As its outstanding properties, such as larger stiffness, lighter weight, excellent heat insulation and dielectrical property, the honeycomb sandwich structure has been widely used in the fields of Aeronautics and Astronautics in recent years. With the instant development of Aeronautics and Astronautics in China, the demand for carrying capacity of spacecraft has increased rapidly, thus it is more and more important to improve the mechanical property of the honeycomb sandwich structure.In this paper, toughening of the resin matrix is studied, and the mechanical property of the honeycomb sandwich structure and its influencing factors are analysed by experiments of machanics and FEM method. It is significant of the results for the design of the honeycomb sandwich structure.Firstly, epoxy resin matrix is toughened by mixing up the polyamide 651 and the 1,2-ethylenediamine in this paper. By FTIR spectrum, flexible molecules and radicals has increased in the matrix because of the polyamide 651. Then the optimization quantity of the polyamide 651 fillings is derived from the mechanical properties testing. The results show that when quantity of the polyamide 651 comes up to 15%, the matrix abtains the best mechanical properties.Secondly, the glassepoxy-aluminum honeycomb sandwich structure is made by the toughened epoxy resin matrix, and the mechanical property of the structure is studied by three-pointbending experiment. Then the influencing factors of the mechanical property of the structure is analysed, and the thickness of the glassepoxy, the laminate orientation and the side length of the honeycomb are considered.Lastly, material constant of the glass fibre panels and the aluminum honeycomb are abtained respectively by tensile testing and Gibson formula. The critical load per unit of mass and the failure mode of the cylinder sandwich structure is studied by the bulking analysis. Then the influencing factors of the mechanical property of the cylinder sandwich structure is analysed, and the laminate orientation, the side length of the honeycomb and the thickness of the honeycomb are considered.It is significant of the results for the design of the honeycomb sandwich structure applied in the fields of Aeronautics and Astronautics.