Outline Design And Optimization Of A Certain Type Marine Diesel Engine Crankshaft

Crankshaft is an important part for marine diesel engine.As its work performance almost determines the performance of the diesel engine work.It also affects the basic operating performance of the entire ship indirectly.So,it can be regarded as the "heart" part of the ship.Therefore,how to optimize the design of marine diesel engine crankshaft become the key goal of research.Since the crankshaft strength represented entire engine,the related crankshaft calculation and analysis were regarded as the critical thing for engine design.Thesis takes a certain type of marine diesel engine crankshaft as the research object.First,traditional calculation was carried out for crankshaft conceptual design stage.General analyzed the dynamics forces,fatigue strength,torsional vibration.Use Visual Basic Applicant program the outline design software.Meanwhile,use Creo,ANSYS Workbench software verified the stress results,as concluded even the calculation result of theoretical formulas is a bit conservative,but still enough to meet the outline design requirements.Secondly,brief introduced several representative algorithm optimization.Then combined outline design software with optimization algorithms iSIGHT platform.Carry out the dimensioning parametric optimization for outline design stage of crankshaft,based on the production and multi-type crankshaft,analyze the variation range of discrete boundary for the dimension parameters and value.Through various types of optimization algorithms rapidly optimized crankshaft design at outline design phrase,computation time was greatly reduced compared to FEM calculations.Third,based on iSIGHT optimized results,compared and checked the improvements of optimization on structural via the Creo parametric modeling and ANSYS Workbench FEM calculation.The focus was put on structural strength,life of fatigue and safety factor for bending and torsion cases during the optimization verification.At last,the model was optimized via topology optimization method.It carried out the optimization based on the mathematical theory of homogenization method utilizing ANSYS Workbench software.APDL program was created to peel off the low densities cells from model,obtained the topological shaped structural.The stress status and fatigue of different topological target ratio was checked.Topological optimization on the model with non-structural shape was carried out,and with the target ratio increased,structural reflect the trend of classic crankshaft changes.So,this method could be reference for the crankshaft structure outline design.This paper presented a concept design and optimization method for crankshaft structure design and topological optimization method was also studied,which provided a new efficient method for crankshaft design and optimization.And also checked the effectiveness of topology optimization methods on crankshaft new conceptual design.Provided idea and reference for crankshaft design optimization.