Fatigue characteristics of crankshaftstructure based on notch fatigue theory
                                                                    LI Jianfeng1, ZHONG Jianfeng2, LIU Zhentao2
(1.State Key Laboratory of Internal Combustion Engine Reliability, Weichai Power Co., Ltd., Wei fang 261061, China;2.Power Machinery & Vehicular Engineering Institute, Zhejiang University, Hangzhou 310027, China)

Abstract: Aiming at the problem that the fatigue limit load of crankshaft is difficult to get quickly and accurately in the design stage, the stress analysis of crankshaft was carried out under the bending moment load, by means of finite element method and the theory of notch fatigue. Based on the actual fatigue failure type of crankshaft, a corresponding notch fatigue coefficient model was established, and the stress concentration factor calculation method and fatigue limit load prediction method of crankshaft were systematically analyzed. The fatigue characteristics of two crankshafts with different material properties and different structures were predicted by means of the above methods, and the accuracy of prediction results and the influence of parameter errors were analyzed. The comparison between predicted and experimental results shows that when predicting fatigue ultimate load of crankshaft based on Peterson notch fatigue model, the correlation prediction results have certain accuracy (error is less than 10%). It shows that the method can quickly determine the fatigue limit load of crankshaft, and has certain practical value for engineering.

Key words: crankshaft; notch fatigue theory; fatigue characteristics