实测数据驱动的挖掘机工作装置疲劳寿命预测

以某型挖掘机为研究对象,建立其工作装置刚柔耦合动力学模型,基于实测油缸位移数据驱动该模型,得到其主要性能参数和典型工况危险部位应力.根据强度理论、动力学仿真结果和工程经验,分析挖掘机动臂和斗杆的易开裂部位,得到典型焊缝高危点,并通过实测应力应变数据进行验证.以刚柔耦合动力学仿真所得的铰点载荷作为输入,利用nCode疲劳分析软件仿真预测挖掘机动臂和斗杆的疲劳寿命.结果表明,实测数据驱动的刚柔耦合动力学仿真可以准确获取挖掘机实际挖掘过程的动力学特性,基于该仿真模型提取铰点载荷并用于预测疲劳寿命的方法切实可行.

Fatigue Life Prediction of Excavator Working Device Driven by Measured Data

In this paper, a rigid-flexible coupling dynamic model is established for a certain type of excavator, the model is driven based on the measured cylinder displacement data and the dynamic simulation is carried out based on the measured displacement of the oil cylinder to drive the excavator, and the main performance parameters and the stress of the dangerous parts in typical working conditions are obtained. Based on the strength theory, dynamic simulation results and engineering experience, the crack prone parts of excavator boom and dipper are analyzed, and the typical high risk points of welding seam are obtained, which are verified by measured stress-strain data. Taking the hinge point load obtained from the rigid flexible coupling dynamics simulation as input, the fatigue life of the excavating boom and stick is predicted through the simulation of nCode fatigue analysis software. The results show that rigid flexible coupling dynamic simulation driven by measured data can accurately obtain the dynamic characteristics of excavator in the actual excavation process, and the method of extracting hinge load and predicting fatigue life based on the simulation model is feasible.