Research On Fatigue Life Evaluation Of Mobile Port Crane Boom

Mobile port cranes play an indispensable role in port cargo transportation.As an important part of mobile port cranes,round pipe welded truss booms have a fatigue life that largely determines the life of mobile port cranes,so it is of great significance to perform fatigue analysis on it.In this paper,the MHC105 mobile port crane boom is taken as the research object,and the fatigue life prediction is evaluated by using modern virtual prototype technology combined with the basic theory of fatigue.First,a finite element model of the boom was established in ANSYS,and a finite element analysis was performed for the two extreme conditions of maximum and minimum amplitude.Through static stress analysis,the strength and rigidity of the boom under limit working conditions were checked and the stress result file was output;through free modal analysis,the first six non-zero natural frequencies and modal shapes of the boom were obtained.The modal neutral file was output and the dynamic characteristics of the boom structure were studied.Then,the rigid-flexible coupled dynamics simulation of the crane boom is performed in ADAMS.The modal neutral file of the boom was used to generate the flexible body of the boom in ADAMS.The rigid-flexible coupled dynamics simulation model of the crane was established through rigid-flexible replacement.The luffing,slewing,and lifting drives were set.Load time history file corresponding to each mode required for fatigue analysis was obtained from the simulation.Finally,the fatigue life of the boom was evaluated using n Code Design Life.According to the fatigue characteristics parameters of the boom material,the SN curve of the boom material was established;the five block diagrams of fatigue analysis were established in n Code,the finite element stress result file and the load time history file were imported and the mapping relationship was established,and the minimum fatigue of the boom was calculated to be 17.95 years.The research results of this paper provide a certain reference for the anti-fatigue design and optimization of the mobile port crane boom structure and even the entire crane.