Fatigue Life of Hydraulic Excavator Undercarriage

To investigate the fatigue reliability of the undercarriage of a medium hydraulic excavator, the method of compiling the load spectrum was studied. Based on the load history sampled on the spot, the eight-level program spectrum for the fatigue test bench of undercarriage was developed. In order to carry out the fatigue test of the undercarriage synchronously, the eight-level program spectrum of four wheels was converted into constant amplitude spectrum with the same phase and frequency by the damage equivalence principle. Meanwhile, the constant amplitude spectrum was calibrated by the damage consistency principle to ensure the reliability of fatigue test. Finally, the fatigue life of the undercarriage was predicted via the constant amplitude spectrum.