Experimental Research And Simulation Analysis On The Flatwise Properties Of Sandwich Composite Panels

Due to the excellent properties, the research for sandwich composite has been continued in recent years. In this paper, high-strength low-stretch polyester industrial filament was used in woven spacer fabric. New type sandwich composite panel was developed by filling foam materials between the fabric space and composite resin to surface layer of the spacer fabric. Then the experimental research and simulation analysis about the various flatwise compressive properties of the new panels were proceeding.Firstly it is to design and manufacture the sandwich composite panel. Because of the flatwise compressive property of sandwich composite panels mainly depends on it’s core structure, the fineness of the binder yarn and filling density of the foam will influence the flatwise compressive property of panels. Five kinds of sandwich composite panels with different binder yarn fineness were made by means of changing the binder yarn fineness. Seven kinds of sandwich composite panels with different foam filling density were made by means of changing the filling quantity of polyurethane foam.Then the flatwise compressive properties of these panels were tested and analyzed.Secondly the experimental results were analyzed. The analysis of the typical Load-deflection curves show that the flatwise proceed included four parts: fitting part, elasticity part, yield part and compaction part. According to the quadratic regression analysis, with the binder yarn fineness increased the load pressure of sandwich composite panel was also increasing. However, when the binder yarn fineness increased to a certain extent, because of the synergistic effect of binder yarns and filled-foam, the increment of sandwich composite plates load tended to inconspicuous. The analysis of the Load-deflection curves show that the flatwise compressive properties integrally increases with the increasing of foam filling density. But the flatwise compressive properties began to decline after a tipping point. According to the one-variable quadratic regression analysis,the flatwise compressive properties were best at a limit foam filling density.Finally the simulation models of composite panels were created basing on the aid of finite element analysis software AYSYS Workbench, and the simulated experiments were proceeded. The stress and stain distributions in the composite panels caused by the flatwise compressive were shown. According to the simulated experiments results, bonding yarn reinforced the composite panels and improved the properties of the panels. The influence of difference of bonding yarn fineness and foam filling density on the flatwise compressive properties was identical to practical experiment.