发动机连杆结构损伤疲劳寿命预测研究

摘要

针对以某发动机连杆结构研究,对连杆进行疲劳寿命预测有助于加快设计和提高发动机质量.连杆在发动机工作过程中承受复杂的载荷,有必要深入研究发动机运行时连杆的疲劳强度.根据现有损伤模型预测疲劳寿命,对连杆的寿命预测结果的准确性有待提高.根据虚拟载荷谱技术,提出了虚拟区间长度的假设,对Manson损伤模型进行有效改进,并从理论层面证明了疲劳寿命预测结果具有收敛性.研究内容包括虚拟载荷谱、原有加载区间的虚拟等分方法、Manson模型改进及损伤修正、疲劳寿命预测进行仿真.结果为疲劳寿命的预测提供了一种新的求解思路.%The engine connecting rod is used as the research object to predict fatigue life.According to the existing damage model to predict the fatigue life,the accuracy of the calculation results needs to be improved.The hypothesis of virtual interval length is proposed based on the virtual load spectrum technology,and the Manson damage model is improved effectively.It proves that the results of fatigue life prediction are convergent from the theoretical level.The research content includes the virtual load spectrum,the virtual division method of the original loading range,the improvements of the Manson model and its correction,and the fatigue life prediction method and solving,etc.Research results were provided for the reasonable prediction for the fatigue life of a kind of new method.