Modeling of 3-D Angle-Interlock Textile Structural Composites

Abstract

A model is developed to predict the in-plane elastic properties of compos ites reinforced with 3-D angle-interlock textile preforms. Straight yarn segments and microcells are utilized in a lamination analogy to predict the in-plane elastic constants. Numerical results for angle-interlock preforms are compared to preliminary test data available in the literature. The effects of varying geometric parameters, namely crimp in terchange, in three different composite systems are discussed and presented in the form of performance maps. In general, stiffer yarn systems exhibit greater ranges of variability in in-plane properties, while the plain weave geometry exhibits greater variability for a given material system. Transverse modulus is higher and Poisson's ratio is generally lower for the plain weave compared to the satin weave, while the shear modulus is generally unaffected by inclination angle. Preliminary experiments, while few in number, show agreement with the plain weave predictions, but agree less well with satin weave predic tions. Knowledge of bundle locations and fiber volume fraction, as well as the accept ability of using straight yarn elements, are key elements to the successful use of the model.