Durability Analysis of the Gear-Rack of a Slat Mechanism

The gear and rack are of significant importance to the operation of the slat. Its performance influences has a significant influence on the safety of an aircraft. The durability of the gear and rack in a slat mechanism is investigated in this paper. A method is presented for the compilation of load spectrum of the aircraft slat mechanism in a flight cycle. The rigid-flex dynamic model of a slat mechanism is built to get the load history of the gear and rack in a flight cycle, considering the deformation of the wing. A flex-flex gear and rack dynamic model is established, and the dynamic contact stress is researched, as the traditional static or quasi-static finite element analysis is not accurate in predicting the meshing force. Durability analysis is made with nominal stress method. The result showed that the damageable positions of the gear are the tooth root and the tooth surface, besides the rack is a life-cycle part.