Experimental and numerical investigation on bending and compressive behavior of carbon-epoxy sandwich panel with novel M-shaped core

Present paper has experimentally and numerically investigated the mechanical behavior of composite sandwich panel with novel M-shaped lattice core subjected to three-point bending and compressive loads. For this purpose, a composite sandwich panel with M-shaped core made of carbon fiber has been fabricated in this experiment. In order to fabricate the sandwich panels, the vacuum assisted resin transfer molding (VARTM) has been used to achieve a laminate without any fault. Afterward, polyurethane foam with density of 80 kg/m3 has been injected into the core of the sandwich panel. Then, a unique design was presented to sandwich panel cores. The study of force-displacement curves obtained from sandwich panel compression and three-point bending tests, showed that an optimum mechanical strength with a considerable lightweight. It should be noted that the experimental data was compared to numerical simulation in ABAQUS software. According to the results, polyurethane foam has improved the flexural strength of sandwich panels by 14% while this improvement for compressive strength is equal to 23%. As well as, it turned out that numerical results are in good agreement with experimental ones and make it possible to use simulation instead of time-consuming experimental procedures for design and analysis.

Analysis of effect of variation of Honeycomb core cell size and sandwich panel width on the stiffness of a sandwich structure

A sandwich structure consists of three main parts i.e. the facing skins, the core and the adhesive. It acts in a way similar to that of the I- Beam. In this research, a sandwich structure has been designed with a regular hexagon honey-comb core made up of Kevlar® and face sheet of carbon fiber. The design has been modelled and the model has also been validated with the experimental and analytical method. Six different configurations of sandwich structures have been proposed. Out of these six, three configurations have the varying cell size i.e. 3.2 mm, 4 mm and 4.8 mm and the other three configurations have the varying panel width i.e. 40 mm, 45 mm and 50 mm keeping rest of the design parameters unchanged. Using ANSYS, analysis has been performed for all these six configurations and equivalent stiffness has been calculated. It has been observed that the honeycomb core cell size does not have a significant effect on the stiffness properties of a composite sandwich panel. The analysis also reveals that with the increased panel width the stiffness of composite panel increases significantly.