The boundary load of the light truck cab fatigue analysis is the force of the cab mounting system, which cannot be directly measured. In the absence of a physical prototype, the fatigue load of the cab cannot be extracted through virtual iteration. Aiming at the problem of fatigue analysis in the early stage of the car-free cab, the virtual proving ground technology is used to extract fatigue load and do fatigue analysis in this paper. Using the virtual road as the excitation, the simulation analysis of the whole vehicle virtual proving ground is carried out, and the wheel center load and the cab mounting force are obtained. Comparing the simulation load with the signal required on the proving ground, it is found that the extracted virtual load is consistent with the actual vehicle load in the time domain and frequency domain. The retention of pseudo-damage of the six-component load of the wheel center can meet the precision control requirements of the vehicle load decomposition. The fatigue life prediction of the cab based on the simulation results of the virtual proving ground, and the comparison with the durability test results of the whole vehicle in the proving ground show that the high-risk area predicted by the fatigue simulation is consistent with the cracking position in the actual vehicle durability test, which can guide the fatigue performance design of the cab. Compared with the traditional technology, the virtual proving ground technology uses a fully digital model to extract a higher-precision fatigue load spectrum at an early stage, which can be used for life prediction and structural design optimization.
