In-plane buckling behaviour and mechanical properties of low-pressure inflatable arches: Experimental investigation and numerical simulations

This study aims to elucidate the failure mechanism of low-pressure inflatable arches, from initial wrinkling to final buckling collapse, and to evaluate their load-bearing performance, providing guidance for engineering applications. Static loading tests were performed, during which the deformation and wrinkle evolution of the inflatable arch under different internal pressures and loading schemes were recorded. A wrinkling simulation method based on Tension Field Theory is developed. By modifying the stiffness matrix, this approach effectively simulates wrinkling behavior of inflatable arches under both concentrated and uniformly distributed loads while significantly improving computational efficiency. Fluid cavity method was adopted to capture the internal pressure-membrane interaction. The validity of the numerical simulation was verified through comparison with the experimental results.The deformation characteristics and wrinkle evolution of character sections under different loading conditions were investigated, and the buckling failure mechanism of the inflatable arch was analyzed. Flattening and wrinkle development at the character section is the critical factor leading to buckling. Failure occurs when the wrinkling angle at the character section reaches 1.25π. Finally, a simplified calculation method for the ultimate bearing capacity of low-pressure inflatable arches is proposed.