The Finite Element Calculation And Optimization Of 8L265 Diesel Engine Block Strength

In recent years, with the continuous development of high-speed, economization and lighter-feedstock of diesel engine, it’s obviously that the strength and stiffness of the block need higher requirements. In this background, regarded 8L265 diesel engine as the research object, this paper makes the simulations to explore the strength and stiffness of the block with the application of finite element theory.The three-dimensional solid model of the block which is established and reasonable simplified by Creo according to the drawings and parameters, and is imported into the finite element analysis software, ANSYS Workbench, in order to create a high-quality finite element model by continuing debugging meshing parameters. Select preload conditions and maximum explosion pressure condition as the study time points by analyzing the stress situation of the block, determine the load constraints and boundary constraints, carry out static and free modal finite element calculation, in order to achieve the statics deformation and stress nephograms of the block under two kinds of conditions and natural frequencies and the corresponding basic vibration mode of free modal Taking a variety of comparative analysis can find out the maximum deformation and stress almost appear the region near all the bolts located the top of the block under the preload conditions, but the corresponding values change significant only where the four bolts around the head of the combustion cylinder and the local stress rises on the region connecting the internal division board with the bearing block under the maximum explosion pressure condition. The maximum modal vibration of non-rigid motion always occurs on both sides of the block skirt and bearing block.For maximum stress, it is confirmed that the strength of block meets safety requirements based on the strength theory. The frequency of the first free modal is much higher than the excitation frequency, so the stiffness of block is in good condition because it is improbable to form the resonance. But the vibration amplitude is larger as the shirt of block is opening and closing, three different solutions are put forward to improve the stiffness of the block. Compared with the consequences of each solution, it could draw the conclusion that the inherent frequency of the optimized model gets improved. The promotion effect of solution above three that the thicker spacer plates are enhanced is the most significant, and the solution that a kind of solid shelf is set up to the bottom can effectively weaken vibration caused by the opening and closing motion of the block skirt.