Fatigue Life Analysis On The Key Parts Of A Large Test Platform For Marine Member Mechanics Performance

The large test platform for marine member mechanics performance ("platform"becalled for short after here)as a one of the main equipment ship for outfitting equipmentcenter,it has important significance to improve our ship outfitting equipment keyproduction process, strengthen the new materials and new technology research anddevelopment. As the first multifunctional test platform for marine member mechanics indomestic, the fatigue strength design and analysis for the platform, not only help to improvethe platform reliability and service life, timely find the weak links, but also can reduce themanufacturing cost, reduce unnecessary waste of materials. At the same time, it can providea reference for the similar product’s fatigue design in the future.Based on the modern mechanics theory, fatigue strength theory, the finite elementtheory, analyzed the platform with the finite element method and life estimation by the finiteelement software ABAQUS and Fatigue analysis software MSC. Fatigue to The specificresearch work and conclusions are as follows:(1) According to the results of the static analysis for the key parts of platform undervarious working conditions. proposing the effectiveness for calculating the large equipmentby the sub-model method, for the fatigue crack estimation provide numerical conditions.(2)With the local stress strain method, proposing the methods and steps to calculatethe platform fatigue crack initiation life, and compile the platform’s load spectrum by themethod of mathematical statistics; calculated the key parts and components of fatigue crackinitiation life for using fatigue analysis software-MSC.Fatigue, Contrasting the relationabout fatigue reduction coefficient and the fatigue crack initiation life, and to research therelationship between them.(3) Analyzed the fatigue crack propagation to key parts with fracture mechanicstheory,and calculated the stress intensity factor of key parts based on the stress of the pushmethod. According to the derived form for Paris formula, and then calculated the fatiguecrack propagation life of key parts by Matlab programming.Research shows that: The sub-model can solve the difficulty of large equipment’sfinite element analysis effectively. It can produce stress concentration in local of platformduring in process. In the conditions of fatigue failure, it don’t have obvious plasticdeformation and the redistribution of load, The fatigue strength in local stress concentrationplace is relatively low. Fatigue reduction coefficient is the important factors for influencing fatigue crack initiation life; Fatigue crack could happen expand under a certain conditions,To be decide whether the crack can extension is the maximum and minimum stressdifference.The crack propagation life is far less than the crack initiation life of the key parts,it needs to make reasonable maintenance system, to avoid the sharp crack expansion in theuse process.