Experimental and Numerical Study of Static Behavior of Bi-stable Hybrid Composite Laminates Containing Three Metallic Strips in its Middle Layer

This study introduces a new lay-ups of bi-stable hybrid composite laminate (BHCL) which consists of 90° unidirectional composite laminas in the upper and lower layers and metallic strips distributed along with the middle layer of 0° unidirectional composite laminas in the middle layer. The static characteristics of the laminates were investigated using the finite element (FE) method and were experimentally validated. The two stable configurations of laminate have identical curvatures with opposite signs. The curvature direction of the proposed BHCLs does not change during snap-through between stable states. This feature will give the engineers more freedom to design morphing structures with desired specifications. The effect of the width, thickness, and material properties of the strips and laminate side length on the static characteristics of the laminate were numerically investigated using the finite element method through Abaqus software. Several BHCLs with different materials, lay-up and dimension were fabricated for verification of the results. The curvatures, out of plane displacement, and the static snap-through load of the laminates were determined experimentally and compared with the results of the finite element method. A good qualitative and quantitative agreement was observed between the FE and the experimental results. The results show that it is possible to adjust residual curvature and load-carrying capability by changing the width, thickness, and material of the strips and laminate geometry.