Simulation analysis and lightweight design of a heavy-duty truck methanol fuel tank

• ·Propose a lightweight aluminum alloy design for methanol fuel tanks. • ·Establish FEM to analyze structural effects on strength and stability. • ·Achieve ∼30% weight reduction while meeting safety requirements. • ·Validate strength, sealing, and vibration durability performance. This study presents a simulation-driven and experimentally validated lightweight design strategy for a heavy-duty truck methanol fuel tank. A high-fidelity finite element model is established to evaluate the tank’s structural response under three representative operating conditions-bump, braking, and turning-using static and modal analyses. Results for the baseline SUS304 tank (2.50 mm wall thickness, 109.59 kg) show that all stresses remain well below the allowable limit and that the first natural frequency (74.03 Hz) avoids the engine/road excitation band. Guided by these findings, a two-stage lightweight design is implemented. First, structural optimization reduces the wall thickness to 2.00 mm, achieving a 15.60% mass reduction while maintaining sufficient strength and dynamic stability. Second, a material-level optimization introduces 5052-T5 aluminum alloy as a practical alternative to stainless steel, addressing both weight reduction and methanol compatibility. The final aluminum alloy tank achieves a total mass reduction of 65.25%, with all stress and modal responses satisfying conservative design criteria. Vibration testing conducted in accordance with GB/T 18296-2019 further confirms the absence of resonance, leakage, or weld cracking, validating the structural reliability of the optimized design. The proposed methodology demonstrates a robust pathway for the lightweight development of methanol fuel tanks and provides engineering references for alternative-fuel commercial vehicles.