Stability and Deformation Degree of Wheel Loaders under the Impact of Debris Flow

Wheel loaders play an important role during emergency rescues under geologic hazard conditions, such as debris flow and landslide. The current literature shows a relative lack of research on the failure mechanism and safety threshold of emergency supplies and vehicles under debris flow. This work presents a method to quantitatively study the interaction between debris flow intensity and wheel loader damage index. The proposed method employs force analysis and finite element modeling to obtain a series of stability thresholds of wheel loaders following the change of debris flow intensity. The results show that the maximum stress of the vehicle frame under the overall impact of over 0.15 MPa exceeds 250 MPa on the side. For the engine compartment shell, the stress of a large area on the shell exceeds the tensile yield strength, and the displacement exceeds 150 mm when impacted by stones at a speed of over $10\mathrm{m}/\mathrm{s}$. The intake and exhaust system, together with the cooling system in the engine compartment, are likely to be damaged. For the fuel tank, the deformation is more than 100 mm when the impact speed of stone exceeds $12.5\mathrm{m}/\mathrm{s}$. The critical impact conditions triggering skidding, tipping, and suspending for the wheel loader are 14 KN, $16.2-29.2\mathrm{KN}$, and $2.4{\mathrm{m}}^3$, respectively. The research results can improve the accuracy of vulnerability assessment of vehicles and emergency equipment under debris flow.