Method to Design Honeycombs for a Shear Flexible Structure 2010-01-0762

Conventional geometric parameters of honeycombs (cell height, h, cell length, l, and cell angle, θ) have been used to find effective properties of honeycomb structures. However, these parameters appear to be difficult to control both a target shear stiffness (4 to 4.5 MPa) and a target level of shear strain (~10%) because the parameters are coupled to each other within a constant design space. A method to design hexagonal honeycombs is derived to design for both shear stiffness and shear flexibility independently by replacing the conventional geometric parameters with two new parameters; effective height, R, and horizontal separation, d. A parametric study with commercial software, ABAQUS, is conducted using the two new parameters to investigate their affects on in-plane effective shear stiffness, G₁₂*, and maximum shear strain, (γ₁₂*)max of polycarbonate honeycombs under a fixed overall honeycomb height of 12.7 mm (0.5 in). The suggested method is expected to be applied to design a lightweight component requiring certain levels of shear stiffness and shear strain simultaneously.