Search

Defects induced in woven textile reinforcements during 3D forming reduce their cured mechanical performance. Numerical modelling is critical to understanding the forming process and the interactions between material, tooling, and process parameters which lead to the formation of these defects. Elastomeric diaphragms utilised in double diaphragm forming experience large deformations and influence the formability of woven textiles. This paper presents a numerical approach to validate the hyperelastic behaviour of an aero-grade silicone diaphragm utilised in double diaphragm forming. Four hyperelastic constitutive models (Neo Hooke, second order Polynomial, second and third order Ogden) are calibrated against uniaxial extension, equibiaxial extension, and planar extension test data with high correlation. The calibrated models are applied to a representative forming experiment with good agreement. The Neo Hookean model was most highly correlated with experiment below 200% strain, whilst the Ogden model shows good correlation across the entire tested deformation range. [ABSTRACT FROM AUTHOR]