A safety analysis of an all-terrain vehicle space frame used explicit dynamics in this research. The main design objective of such a frame is driver safety while enhancing structure rigidity. Explicit dynamics analysis provides the designer with the effects of the impact on the structure frame members regarding energy, dynamic stress, and acceleration. The tubular frame 3D model is introduced in SolidWorks considering the powertrain system and driver weights. Then, the frame is subjected to a frontal crash scenario to a fixed full-width rigid barrier in the ANSYS workbench. The explicit dynamics model improves the accuracy and computational efficiency of the analysis, however, a validation was used the lumped mass-spring (LMS) system is executed in MATLAB/SIMULINK environment as an alternative computation technique to ensure FEA simulation results. A 3 DOF dynamic model is utilized to investigate the system's equations of motion in the forward direction. Three main zones are considered including the front bulkhead, roll-cage, and rear engine compartment to represent the mass model accelerations. The deflection values of the vehicle frame according to the frontal crash loading condition are studied, however, the frame members' stiffness was measured experimentally. Finally, the two analysis methods were compared for vehicle frame safety evaluation. The results of the explicit dynamics simulation along with the calculated lumped-mass spring system results indicate that the designed space frame achieves the requirements of structure rigidity regarding the frontal crash scenario condition, and the results of the two models satisfy the model rigidity in terms of deflection, energy absorption and vehicle acceleration.