Mechanical response characteristics and cushioning of sealed airbags under different length–diameter ratios.

This article focuses on the blast-resistant cushioning performance of sealed airbags used as rapid sealing structures in underground coal mines to contain mine fires and mitigate explosion hazards. Through blast cushioning experiments and numerical simulations using ANSYS/LS-DYNA software, the study analyzes how different length-to-diameter (L/D) ratios affect the mechanical response, deformation, stress distribution, and energy absorption of airbags under shockwave impact. Experimental results indicate an optimal L/D ratio range of 1.25:1 to 1.56:1 for small-scale airbags, while full-scale simulations suggest an optimal ratio near 0.75:1, with both highlighting risks of stress concentration and failure modes at extreme lengths. The research establishes an energy absorption model for single-chamber airbags and finds that reflected shockwave energy remains constant regardless of airbag length, providing theoretical guidance for designing effective blast-resistant airbag seals in mine safety applications.