CAE Simulation Analysis For Static And Dynamic Strength Of Engine Connecting Rod

The connecting rod, an important component and mainly moving part of the internal combustion engine, has complicated structural shape and loading condition. To a large extent, the reliability and using life of the connecting rod have a great effect on the internal combustion engine. With the development direction of the high-speed, high power and high-load on the internal combustion engine, the working environment of the connecting rod has become increasingly harsh. Therefore, the movement and loading analysis, the structure strength calculation and the dynamic characteristics study of the connecting rod are of great significance to the design and optimization of the connecting rod.A type of connecting rod of diesel engine was considered in this thesis. And the works had been completed as follows:1. The movement and force conditions of the connecting rod were analyzed. Firstly, the kinematics parameters of the connecting rod, including angular displacement, angular velocity and angle acceleration, were calculated. Secondly, the four main loads which the connecting rod endured were calculated in the load analysis process. Finally, the loads under the maximum draw and pressure conditions were calculated, which provided the necessary boundary conditions for the subsequent calculation.2. Based on the finite element method, the finite element model of the connecting rod was built. The following researches were made. In the pre-load condition, the impact of element type on the stress distribution was discussed. In the maximum tensile and maximum pressure conditions, the effect on the stress distribution by the different ways of loads setting and boundary constraints definition was taken into account.3. The dynamic character of the connecting rod was studied by using the modal analytical technology. The modal character was studied by using the FEA method and test method, and the mode frequency and vibration shape were obtained, which could provide the basis for the following multi-body dynamics analysis. Finally, the contrast verification of the calculated results was made.4. The multi-body dynamics simulation model of the connecting rod was built by using the multi-body dynamics software. The movement parameters and the accurate load boundary conditions of the connecting rod in work cycle were obtained by means of the numerical simulation. And the lubrication performance of the connecting rod bearing was analyzed.5. The three-dimensional transient stress field of the connecting rod was calculated by using the finite element software, the dynamic stress distribution in a cycle of the connecting rod was obtained, and the assembly load considered whether or not for the calculation was compared. The comparison between the parts of the crank angle of the stress contours and the static calculation results were made at the same time. The analysis shows that the dynamic stress simulation result of the connecting rod is more reasonable and more closely to the actual situation.