A Numerical Study On The Friction And Wear Properties Of Finger Lock In Aircraft Landing Gear

The retractable function of landing gear is an important factor affecting the safety of aircraft,locking mechanism is an important component of landing gear retraction system,its failure could lead to flight accidents.In this paper,the finite element simulation method was adopted,and the friction and wear problems of finger lock in aircraft landing gear were studied.The finite element model of finger lock considering the dynamic coefficient of friction was established in the paper,the procedure was adopted in the movement of finger lock with Abaqus/Explicit explicit solver,the friction and wear test of finger lock was designed to verify the simulation results,the modeling process of finger lock simulation model and the application situation were shown in detail.Based on the approach of utilizing user subroutine to realize secondary development in ABAQUS,the rate dependent dynamic friction coefficient was proposed,and the user subroutine programmed with Fortran was coded to develop the rate dependent dynamic friction model so as to complete the friction calculation of the movement of finger lock.The results indicate that the difference between friction simulation results and experiment data is small,the finite element model of finger lock is established correctly and reasonably,proving the effectiveness of finite element analysis to analyze the friction simulation of finger lock.The paper referred to the wear theory proposed by Cho J.R.,the nodal frictional energy density rate was adopted as the index to assess the wear severity,and the wear simulation analysis was achieved by realizing the secondary development of post-process through ABAQUS scripting interface.The procedures and details of programming Python language to graphically display the nodal frictional energy density rate distribution in contact footprint regions of finger lock chuck was described in the paper.The wear region and wear severity of finger lock chuck can be observed in the wear simulation results,and the distribution of frictional energy density rate is basically accordant with the wear test results,proving the validity of the finite element analysis method of wear properties.The dynamic friction model user subroutine was programmed to add new codes,aiming to export the nodal slip velocity data in contact footprint regions of finger lock chuck,finally the vector visualization of nodal slip velocity was accomplished in Abaqus/Viewer module.