Hybrid analysis approach to evaluate the structural response of the filament wound composite pressure vessel subjected to varying pressure conditions

• Optimized a filament-wound composite LPG cylinder using ±54.65°, 15°, and 80° ply angles for strength. • Validated structure via classical laminate theory and FEA in ANSYS and ABAQUS. • Achieved 15 MPa burst pressure and 2 MPa safe operation with a 7.5 safety factor. • Reduced weight by 61.5% versus steel cylinders. • Fabricated and hydrostatically tested with no leakage. Filament wound composite pressure vessels are widely used as lightweight alternatives to conventional steel cylinders for low and medium pressure applications. This study presents a systematic methodology for the design, analysis, fabrication, and validation of a type IV composite LPG pressure vessel consisting of an HDPE liner and an E-glass epoxy overwrap. The design methodology integrates analytical modeling based on Classical Laminate Theory (CLT) to evaluate laminate stiffness, stresses, and strains. In addition, netting analysis is employed to determine the optimum fiber winding angle i.e., ±54.65°, for efficient vessel curvature and load transfer. Finite element simulations are used to validate the analytical results and evaluate the structural response of steel and composite cylinders under working (2 MPa) and burst (15 MPa) pressure conditions. Plies load bearing efficiency increased with fiber orientation up to approximately 55° and decreased at higher angles, reflecting reduced axial load transfer. Progressive damage behavior of the composite layers is assessed using the HASHIN failure criteria to identify fiber and matrix dominated failure modes. The optimized composite cylinder is fabricated using a filament winding process and experimentally evaluated through hydrostatic testing to verify leak tightness and structural integrity at the working pressure. The results demonstrate good agreement between analytical, numerical, and experimental results. Compared to a conventional steel LPG cylinder, the proposed composite design achieves a significant reduction in weight while safely sustaining the required operating pressure, confirming the effectiveness of the adopted hybrid methodology for composite pressure vessel design.