Fatigue Life Analysis And Structural Optimization Of Scissors Aerial Work Platform

Scissor aerial work platform is widely used in various fields such as engineering construction and municipal maintenance due to its simple manipulation,stable operation,strong bearing and adaptability.As a critical component of the scissor aerial work platform,the scissor mechanism affects the safe and reliable operation of the platform.Under repeated fluctuating load,the structural strength and fatigue of the scissor mechanism become the main ineffective manifestations of operating platform.The strength and fatigue performance of the structure are directly related to stability and safety of the whole platform,therefore it is crucial to study the performance of both two.In this paper,the scissor mechanism of a certain scissor aerial work platform was taken as the research object,and its theoretical calculation model and finite element simulation model were established.The theoretical calculation analysis,dynamic simulation analysis,inertia release analysis and fatigue life analysis were carried out.The reliability of the finite element simulation model and theoretical model were verified through stress test experiments and pressure test experiments.Finally,the crucial components of the scissor mechanism were optimized based on the finite element simulation results.The main research contents and results are listed as follows:(1)The mathematical modeling method was applied to calculate and analyze the thrust of the hydraulic cylinders and the hinge point force of lifting platform of the scissor mechanism,and based on the genetic algorithm,the installation positions of hydraulic cylinders were optimized;By using 3D modeling software and finite element analysis software,the mechanical-hydraulic combined rigid-flexible coupling multi-body dynamics simulation of the scissor mechanism was completed.According to the simulation results,the following analysis was developed on the scissor mechanism: comparative analysis of simulation results of hydraulic cylinder thrust and pressure test results,the stability analysis of the scissor mechanism,the strength analysis of the scissor arms and the extraction of the nodes load spectrum.The correctness of the dynamic simulation model was verified,the stability of the scissor mechanism which meets the design requirements was proved,the most dangerous working condition of the scissor arm was determined.(2)Based on the dynamic simulation results,suitable measuring points on the scissor arms were selected for stress test experiment.Comparing experimental resultswith the simulation analysis results,The correctness of the dynamics analysis results was verified and the rationality of the design and optimization based on dynamics analysis was ensured.(3)Based on the dynamic simulation results,by using a higher-precision scissor arm mesh model established in Hypermesh,the inertial release analysis of the scissor arm under extreme condition and under unit loads was conducted.The correctness of dynamic analysis was further verified,and the static analysis results of the scissor arm structure required for fatigue analysis were acquired.In addition,n Code software was applied to the calculation of the fatigue life of scissor arms,and the positions where the maximum fatigue damage of the scissor arms were determined.Eventually,based on the results of fatigue analysis and static analysis,the structure of the scissor arms was optimized,and it was reanalyzed the structures for the optimized scissor arms.The analysis results show that the optimized structure meets the strength and fatigue life requirements.