Efficient helicopter skid landing gear dynamic drop simulation using LS-DYNA

Stringent military requirements and design targets underscore the need to develop a robust methodology to analyze the structural behavior of helicopter skid landing gear under dynamic loading conditions. To survive high-energy impacts, the skid landing gear must be designed to provide adequate energy absorption. Bell Helicopter has developed a non-circular crossbeam to optimize design requirements for the skid landing gear. Previous analytical work using MSC.Dytran(R) focused on analyzing circular crossbeams and was later extended to analyze rectangular crossbeams with shell element representation. However, excessive computational time precluded the methodology from becoming a viable design tool. This paper focuses on the development of an efficient method for skid landing gear dynamic drop analyses by using a nonlinear hollow rectangular beam element representation. The method, which reduced computational time from 1-2 days to 12 minutes, employs LS-DYNA(R) to simulate the response of the skid landing gear for UH-1Y helicopters during hard surface impact. Four standard landing conditions are analyzed and correlated with drop test results.