The Sealing Performance Analysis And Fatigue Life Predication Of The Seals Of Certain Type Aircraft Actuator

Hydraulic actuator is an important component of aircraft hydraulic system. And its oil spilling, which mainly caused by the failure of rubber o-ring, is the main factor that impedes its high efficiency of the hydraulic system and jeopardizes the safety of aircraft. Thus in this research, the rubber o-ring of the servo actuator is considered as the research object, and an analysis is taken on the main elements of the spilling and fatigue life prediction.Firstly, the geometric nonlinearity and contract nonlinearity of rubber material are also taken into the comprehensive consideration, establish the axisymmetric deformation finite element model of o-ring by the finite element software. The computation simulates the variation relationship between contact stress and Mises stress with ratio of compression and fluid pressure.Secondly, let me take an coupling analysis on the thermal structure of robber o-ring. The influence came from temperature on the displacement, contact stresses and Mises stress are taken into the analysis based on indirect coupling method, Knowing the influence of thermal stress less than mechanical stress on the sealing properties. the aging of rubber caused by temperature are also take into consideration.Thirdly, according to the existing two-level model of hydraulic servo actuator, using the mechanical dynamics analysis software Adams, established the simulation model of hydraulic servo actuator with non-ideal constraints, the change of the contact stress of rubber o- ring are analysis when a error happening in installation. Additional contact force far greater than ideally contact force.At last, the dangerous section of the robber rubber sealing ring, which is prone to fatigue, will be identified according to the results of nonlinear finite element method. Then this research regards the tear rang as the fatigue damage parameter, calculate the fatigue life of the O-ring's node of dangerous section, fatigue life for 8333 hours, and offers theoretical basis for the prediction of the fatigue life.