Study On The Possibility Of Substituting GN16Engine Crankshaft Material Nodular Cast Iron For Non Quenched And Tempered Steel

Based on GN16engine crankshaft substituting nodular cast iron for nonquenched and tempered steel as the research object, structure analysis, processanalysis and test for crankshaft after changed to nodular cast iron are performed.According to the engine kinematics, dynamics, balance, the theory of fluidlubrication and the torsional vibration theory, the finite element model of crankshaftsystem for an inline4-cylinder4-stroke engine is established, and using nonlinearmulti-body system dynamics software AVL/Excite, multi-body system dynamicsmode of rankshaft system is established. On the basis of the fatigue analysis theory,system dynamics equation of forced vibration and Reyonds equation, the crankshaftsystem characteristics such as dynamic fatigue results analysis in the free mode, mainbearing load, stress of dangerous speed, fatigue safety factor and its distribution, theminimum fatigue safety factor under the different fatigue limit of material,one-dimensional torsional vibration analysis in one order and two order torsionalinherent frequency, hub synthesis of torsional vibration amplitude, single ordertorsional vibration amplitude, hub dissipated power, cyclic speed irregularity, and thehydrodynamic lubrication analysis of crankshaft system in the minimum oil filmthickness and maximum bearing unit load of main bearing and connecting rod bearing,are respectively analyzed.After two times of GN16engine crankshaft design modification, the abovestructure analysis, crankshaft fillet rolling pressure adjustment and the measurementand analysis of fillet rolling depth, finally400H alternating load durability test isverified and passes.The paper finally gives the summary data for the substituted GN16enginecrankshaft material in the aspect of cost reduction, weight reduction, machinabilityimprovement etc. Combined with the actual situation of TG15crankshaft, which willbe substituting nodular cast iron for non quenched and tempered steel, theimprovement suggestions are given in the aspect of structure analysis, processanalysis and test etc..