Experimental and numerical investigation of effect of shape of ribs on flexural behavior of curved composite sandwich panels with lattice core under

Sandwich panels have become popular in various industries like aerospace, marine and automotive as a lightweight structure that has high stiffness and strength to weight ratio. Since many of composite structures that been used in these industries has curvature, there is a desire to investigate the effect of curvature on flexural behavior of these structures. Composite Sandwich panel with lattice core are made from thin composite shell connected to both sides of a series of composite ribs. In this research, the flexural behavior of curved composite sandwich panels under three point bending, has been investigated experimentally and numerically. For this purpose, two types of sandwich panels with core of square and isogrid ribs were considered. Grids are fabricated by filament winding method. Samples were subjected to three point bending test. The test has been numerically simulated by FEM in Abaqus. Tension tests are conducted on grids and shells in order to obtain mechanical property of them. Also, structure failure were predicted for numerical simulations. Good correlation between experimental and FEM analysis was obtained. Results show that sandwich panel with isogrid shape of core has 7% more bending stiffness compared to square-shaped core sandwich panel. Results also indicate that the ultimate strength of sandwich panel with isogrid core is 7.5% higher than the sandwich panel with square shape of core.