Analysis And Test For Dynamic Performance Of Landing-gear Retraction And Extension

A landing gear is one of the key components of an aircraft, whose working performance directly affects the flying security and the airplane's takeoff and landing performance. Among all the modern aircraft's components, the disabled probability of the retraction system has been up to 34.4%. Thus, it's meaningful to study the retraction system. In terms of virtual production test, the paper analyzes the dynamic performance of the retraction system for an aircraft.Structure forms and retraction forms are analyzed, and carried on the movement analysis in view of some landing-gear retraction system with analytics. Retraction equation of motion and the corresponding curve are given based on symbolic method. The kinematical model of the aircraft retraction system is built in CATIA. Based on it, the kinematical method of retraction system is studied, which provided technical basement for the retraction performance and the machine's interference analysis.Based on CATIA and ADAMS software, a virtual model is developed to use for the performance test of some landing gear retraction system, and retractable dynamics simulation is carried out. The main factors which affect the dynamic performance of retractable landing gear are analyzed emphatically.A test system of landing gear retraction is developed, including the test bench, the hydraulic system, the control system and the measurement system. The problem of loading separately is solved in retraction and extension process of landing gear. The maximal error in loading simulation is less than5% . Compared simulation results and hydraulic actuator load, the average error in is about 3% . The experimentation can work several hours continuously. And, it has been completed more than 7000 times. The test Verify the correctness of the simulation results. Also, the research can provide support for subsequent theoretical research and experimental work.