Que Tianyi, Jiang Dongdong, Sun Songsong, Gong Xiaolin
College of Automobile and Traffic Engineering, Nanjing Forestry University, Nanjing 210037, China.
Li Auto Vehicle Control Operation System, Hangzhou 310000, China.
Materials (Basel). 2023 Nov 16;16(22):7186. doi: 10.3390/ma16227186.
The high-cycle bending fatigue experiment is one of the most important necessary steps in guiding the crankshaft manufacturing process, especially for high-power engines. In this paper, an accelerated method was proposed to shorten the time period of this experiment. First, the loading period was quickened through the prediction of the residual fatigue life based on the unscented Kalman filtering algorithm approach and the crack growth speed. Then, the accuracy of the predictions was improved obviously based on the modified training section based on the theory of fracture mechanics. Finally, the fatigue limit load analysis result was proposed based on the predicted fatigue life and the modified SAFL (statistical analysis for the fatigue limit) method. The main conclusion proposed from this paper is that compared with the conventional training sections, the modified training sections based on the theory of fracture mechanics can obviously improve the accuracy of the remaining fatigue life prediction results, which makes this approach more suitable for the application. In addition, compared with the system's inherent natural frequency, the fatigue crack can save the experiment time more effectively and thus is superior to the former factor as the failure criterion parameter.
高周弯曲疲劳试验是指导曲轴制造工艺，尤其是大功率发动机曲轴制造工艺的最重要的必要步骤之一。本文提出了一种加速方法来缩短该试验的时间周期。首先，基于无味卡尔曼滤波算法和裂纹扩展速度对残余疲劳寿命进行预测，从而加快加载周期。然后，基于断裂力学理论对修正训练段进行研究，显著提高了预测精度。最后，基于预测疲劳寿命和修正的SAFL（疲劳极限统计分析）方法，给出了疲劳极限载荷分析结果。本文得出的主要结论是，与传统训练段相比，基于断裂力学理论的修正训练段能显著提高剩余疲劳寿命预测结果的准确性，使其更适合实际应用。此外，与系统固有固有频率相比，疲劳裂纹作为失效判据参数能更有效地节省试验时间，因而优于前者。
