Load Spectrum Acquisition of Earth-Moving Machinery Based on Digital Twin

Load spectrum acquisition is always a conundrum for the fatigue analysis of earth-moving machinery. The paper proposes a load spectrum acquisition method of key hinge points for work device based on digital twin technology. Discrete element method and rigid-flexible coupling dynamic matrix model are adopted to build the digital twin, which is driven by the practical operation data obtained from Industrial Internet of Things. With the comparison of actual stress acquired by Internet of Things and simulated stress, the simulation parameters are optimized by Latin Hypercube response surface to modify the acquired load spectrum. Besides, the method is applied to a medium excavator. After the experiment, it's verified that the maximal amplitude error between acquired load spectrum and actual load spectrum is 7.1%. The application of this method not only acquires the load spectrums of different soils, but also takes the operators' operation habits for earth-moving machinery into consideration. Therefore, it plays a guiding role in the engineering practice of the calculation of residual life for earth-moving machinery.