Composite skid landing gear design feasibility study preliminary results are presented. Load factor under limit loads and local ply stresses and strains are evaluation metrics. Limit Drop Test as per FAR Part 27 has been simulated for multiple landing scenarios from a drop height of 508 mm (20"). Composite laminate selection was done based on comparative and iterative study of 7 fibers and 2 matrix systems. Dynamic explicit finite element analysis (FEA) has been conducted using ABAQUS™. Load factors for a 48 ply all composite skid landing gear are within 4-6g. An all composite design results in over 40% weight saving in comparison to a 1/4" wall thickness aluminum skid landing gear. Strains are high in regions close to both cross member radii. Metal-composite and metal-hybrid composite designs result in lower load factors with weight saving up to 49%. Hybridization benefits of metal are region dependent only. A 48 ply design, with Ke49/PEEK composite skids, 1/4 " thick Al 7075 cross member radii bends and rest of the landing gear of IM7/PEEK (or IM7/977-3) shows desired performance. Physics based strength failure criteria are suggested instead of Maximum strain theory for further study.
展开▼
