Sun Songsong, Yu Xiaoli, Liu Zhentao, Chen Xiaoping
Power Machinery & Vehicular Engineering Institute, Zhejiang University, Hangzhou, China.
School of Mechanical Engineering, Ningbo University of Technology, Ningbo, China.
PLoS One. 2016 Dec 30;11(12):e0167722. doi: 10.1371/journal.pone.0167722. eCollection 2016.
For the critical engine parts such as the crankshaft, the fatigue limit load is one of the most important parameters involved the design and manufacture stage. In previous engineering applications, this parameter has always been obtained by experiment, which is expensive and time-consuming. This paper, based on the theory of critical distance (TCD), first analyzes the stress distribution of a crankshaft under its limit load. In this way, the length of the critical distance can be obtained. Then a certain load is applied to a new crankshaft made of the same material and the effective stress is calculated based on the critical distance above. Finally, the fatigue limit load of the new crankshaft can be obtained by comparing the effective stress and the fatigue limit of the material. Comparison between the prediction and the corresponding experimental data shows that the traditional TCD may result in bigger errors on some occasions, while the modified TCD proposed in this paper can provide a more satisfactory result in terms of the fatigue limit for a quick engineering prediction.
对于诸如曲轴等关键发动机部件，疲劳极限载荷是涉及设计和制造阶段的最重要参数之一。在以往的工程应用中，该参数一直通过实验获得，这既昂贵又耗时。本文基于临界距离理论（TCD），首先分析了曲轴在其极限载荷下的应力分布。通过这种方式，可以获得临界距离的长度。然后对由相同材料制成的新曲轴施加一定载荷，并根据上述临界距离计算有效应力。最后，通过比较有效应力和材料的疲劳极限，可得到新曲轴的疲劳极限载荷。预测结果与相应实验数据的比较表明，传统的TCD在某些情况下可能会导致较大误差，而本文提出的改进型TCD在疲劳极限方面能够为快速工程预测提供更令人满意的结果。
