Composite Skid Landing Gear Performance and Laminate Tailoring for Reduced Load Factor under Limit Loads

摘要

Composite skid landing gear performance was evaluated for IM7/8552 and AS4/8552 crossmember beam designs. Limit drop test as per Federal Aviation Regulation (FAR) Part 27 was simulated by dynamic finite element analysis from a drop height of 508 mm (20 inches), using ABAQUS™. Tsai-Wu, and LaRC04 failure criteria were used to predict failure and fracture modes in the composite beams. Matrix cracking and fiber kinking are commonly predicted, mostly in 45°/-45° plies. IM7 fiber is the final selection for the composite beams. Five laminate families were evaluated for load factor reduction with single variable parameterization and strength constraints. Laminates including 75°/-75°fiber orientations have lowest load factors. Strength constraints result in a reduced level landing load factor of 4.17g for [0/90/45/-45]6s laminate. Adhesive bond between the composite beam and metal radii as well as a filament wound metal-composite joint were analyzed. Only the filament wound joint shows sufficient strength.