Dynamic air permeability model of parachute fabrics and material parameters sensitivity analysis

Abstract

To explore the effect of material parameters on dynamic air permeability of parachute fabrics, the relative porosity model was obtained by considering the yarns stretching in length and shrinking in cross-section under the transient pressure differential. A parachute fabric dynamic air permeability model with fabric material parameters was established based on the Ergun equation. The results showed that the new model is more accurate and is applicable of higher pressure differential compared with other traditional methods. On this basis, the sensitivity analysis of the effect of the fabric structural parameters and mechanical parameters on dynamic air permeability was conducted. The results showed that: (1) the dynamic air permeability decreases with increasing fabric thickness and fabric Young’s modulus, and increases with increasing fabric test area and fabric Poisson's ratio, and (2) the dynamic air permeability is more sensitive to the fabric thickness and is less sensitive to the fabric tested area, The dynamic air permeability is significantly affected by fabric Young’s modulus, but slightly affected by fabric Poisson's ratio.