Characterizing the mechanical properties of drop stitch inflatable structures

Abstract

This study investigates the mechanical properties of drop stitch inflatable structures with specific reference to inflatable stand up paddleboards. A sample of drop stitch material was fabricated and simple beam bending tests were performed at different pressures. This data was then used to invalidate a developed model for the deflection of the sample. High standard deviations indicate that the pressure inside the tested sample was changing throughout the duration of the tests. An elastic modulus for the material was determined using the internal pressure. The results showed an elastic modulus on the order of 60 MPa. The fabrication process and results led to the conclusion that one of the main advantages of drop stitch technology is its ability to create unique shapes that are unable to be constructed with an inflatable alone. The results also showed that the beam becomes stiffer with an increase in internal pressure and that simple beam theory is invalid for characterizing drop stitch inflatable structures.