The Nose Landing Gear Load Analysis Of Carrier-based Aircraft Take-off

In all ways of carrier-based aircraft take-off, catapult launch is becoming the most widely used technology. Catapult launch has lots of advantages such as efficient, safe, meeting more complicated working condition and so on. This technology has broad prospects, and it’s the main development direction of the way carrier-based aircraft take off in the future. The ejection force of carrier-based aircraft catapult launch is acting on the front aircraft landing gear, therefore, the dynamics analysis of carrier-based aircraft catapult launch and the load analysis of nose gear has important theoretical significance and engineering practical value.In this paper, first according to the actual working condition of the carrier-borne aircraft catapult launch, a mathematic model of the landing gear system and the whole aircraft is build, derived the aircraft catapult launch dynamics equations at each stage. Then on account of the theory of multi-body system dynamics method, based on the software platform ADAMS, set up the nose landing gear and the whole aircraft virtual prototype model, analyzes the process of the ejection of the aircraft catapult launch. Get the results of load case and maximum load of the nose gear in different variables such as the fast-extension motion of the nose gear, different aircraft mass and ejection force. Contrast and analyze the dynamic response and takeoff performance of the aircraft in those different variables. The results provide a reference in the nose landing gear design.The results show that in the process of the aircraft catapult take-off, the fast-extension motion of the nose landing gear can effectively reduce the sink of the aircraft, the bigger fast-extension motion makes the smaller sink of the aircraft, and provide a better flight path. Ejection force mainly affects the flight path. If the ejection force is too small, the aircraft can’t get enough speed to takeoff safely after leaving the aircraft carrier. Large ejection force will increase the axial load of nose landing gear, shorten the take-off run time, but the aircraft won’t get enough attack angle to take-off safety. The increase of the aircraft mass can also lead the increase the load on the nose landing gear.