DESIGN AND ANALYSIS OF ROLL CAGE OF AN ALL-TERRAIN VEHICLE (ATV)

The roll cage serves as the primary structural shell and driver safety framework for All-Terrain Vehicles (ATVs), engineered to withstand high-speed off-road collisions and severe rollover events.This study presents a comprehensive structural design, material selection framework, and Finite Element Analysis (FEA) of an ATV roll cage compliant with SAE BAJA design specifications.Three candidate structural steels-AISI 1020, AISI 1018, and AISI 4130 Chromoly-were systematically evaluated based on yield strength, strength-to-weight ratio, bending stiffness, weldability, and fabrication viability.AISI 4130 was selected due to its high yield strength (460 MPa) and superior energy absorption characteristics.A 3D CAD framework was modeled using SolidWorks weldment features, followed by static structural impact simulations in ANSYS Workbench under multi-directional loading conditions: Front (8g force / 7503 N), Rear (6g force / 7503 N), Side (4g force / 5625 N), and Rollover (3450.59N).Finite Element Analysis yielded minimum factors of safety of 1.826 for front impact, 1.0411 for rear impact, 1.0827 for side impact, and 1.538 for rollover impact, with maximum von-Mises stresses remaining safely below the yield strength threshold.The results demonstrate an optimal integration of driver ergonomics, structural rigidity, dynamic impact resistance, and mass efficiency.