The Research Of The Connecting-rod In Transient Dynamics Simulation And Experiment

Connecting-rod is one of the most important moving parts of diesel engine. It's strength and stiffness largely determine the reliability and service life of the diesel engine. Study connecting-rod force change and stress distribution in the working process, provides an important theoretical basis for the design and optimization of diesel engine.In the process of the static finite element calculate with the connecting-rod, I establish the physical characteristics of the bolt threads, using the penalty function contact algorithm,simulated bolt threaded screw holes on the contact surface with the force of the transfer process. Calculate the stress distribution of the connecting-rod when consider bolt preload,bearings and bushings with interference fit. Analyze the strength of the connecting-rod in the assembled state, largest tension state, and maximum compression state. Traditional method simplified thread feature and ignore the interference. I established a finite element model of the crank-link mechanism system. Calculate the stress of the connecting-rod in three working cycles. Analyze calculation results in the second working cycle. Summarize stress variation in the working cycles. Using the existing experimental conditions design a tension and compression experiment with the connecting-rod. Contrast the experimental results and static calculate result and transient calculate result to verify the reliability of simulation results.Contrast no thread feature simplified connecting-rod and thread feature simplified connecting-rod result. We found that in the part of connecting-rod big end transition and small end transition,no simplify thread features connecting-rod local stress distribution changes along the rod centerline ladder structured, but simplified thread feature connecting-rod stress distribution is no rule. The two methods of calculation and experimental results are compared, no simplify thread feature connecting-rod results is more close to the objective reality. Analysis of transient dynamics calculation found that pressure the connecting-rod the stress increases faster the side of away from the centerline than the other side. On the contrary, the connecting-rod is in a stretch condition. Comparison three kinds of analysis result that the experiment result,the static calculation analysis and the.transient dynamic analysis result. Transient dynamic analysis and static analysis calculation results conform to the objective reality.