Research On Dynamics During Catapult Takeoff Of Carrier-Based Aircraft

There are very complex dynamic problems during the Carrier-based aircraft taking off and landing. In this thesis, the flex-rigid virtual prototype model had been built in LMS Virtual. lab to simulate the whole catapult launch process which contains six stages of carrier-based aircraft.The catapult security and dynamic response of the target aircraft were analyzed. The main contents of this dissertation are summarized as below:1. This thesis introduced the advantages and disadvantages of the take off way of catapult, illustrated the importance of the research on the carrier-based aircraft catapult take-off technique. And research status in this field were reviewed2. Considering the most common situation and referencing to some of the existing model, the deck motion mathematical model, the body sub-model (wing and fuselage), landing gear (the front and main landing gear) model were established. Finally, the calculation of catapult load was discussed.3. According to the two design criteria, the application that the virtual prototype model of multi-body dynamic analysis, Simulation results show that: the target aircraft meets the criteria requirements, and can take off safely; landing gear fast-extension motion can reduce the sudden subsidence; The deck motion have a certain influence on the movement of aircraft.4. Based on the fixed interface modal synthesis method, the flexible nose landing gear models had been built. The flexible coupling dynamics simulation results show that: after the nose gear separated from the hold bar, there is a larger "squat" load in the main landing gear; the long launch bar and the flexible nose landing gear reduce the lateral stiffness coefficient; the dynamic response caused by separation is related to the size and decay rate of separate load.