Research On Fatigue Life Of The 18m~3 Grab Dredger Structure Based On The MSC.Fatigue

With the rapid development of the world economy,driven by the world's water transport and trade continues to grow,but the port waterway maintenance and dredging serious lag,greatly hampered the continued growth of trade.Grab dredger as a professional channel dredging engineering machinery,the use of increasingly frequent,the functional requirements are getting higher and higher.Therefore,the design method of grab dredger should be improved constantly to improve the function,economy,reliability and safety.At present,in the grab dredger design has been extensive use of computer simulation technology,but only stay in the static analysis and simplified analysis stage.Usually the design staff in accordance with the conventional design process,according to the actual work of grab dredger and experience to select a series of more conservative coefficients for strength,stiffness and stability of the calculation and verification to ensure that the grab dredger in the normal use The process of reliability and security,resulting in the design cycle of the dredger is too long,the design accuracy is not high.During the use of the grab dredger,the local structure of the welding,cracking and fracture occurred,the life of the dredger is largely dependent on the life of the metal structure.Therefore,it is very important to evaluate the fatigue strength and fatigue life of the metal structure of the grab dredger.In the early stage of the design of the grab dredger,fatigue life analysis of the structure can be carried out by using the finite element fatigue simulation.The fatigue life of the grab dredger can be obtained,and the unreasonable life distribution can be avoided or optimized by modifying the design.In this paper,the finite element model of grab dredger structure was established by ANSYS finite element software with 18m~3 grab dredger.According to the different working conditions of dredger,four typical workers Static analysis and modal analysis,and the results into the professional fatigue analysis software MSC.Fatigue,to complete the grab dredger structure S-N curve correction,according to the actual work of grab dredger,the preparation of grab dredging Time history curve of the grab dredger,and the finite element analysis results of the grab dredger are combined to complete the fatigue life analysis of the grab dredger.The results of this study will reveal the fatigue life of the structure in front of people,so that designers and users can accurately and easily evaluate the rationality of structural design and performance,help to improve product fatigue performance,shorten the development cycle,Reduce production and use costs,improve economic efficiency.The research results of this paper have certain theoretical and practical value for similar ship machinery and equipment.