Analysis of tow deformations in textile preforms subjected to forming forces

Tow deformations in a textile preform subjected to forming forces and the influence of these tow deformations on composite laminate properties have been studied. Tow geometry parameters are measured with the help of microscopy and image processing techniques. 3D geometrical models have been developed from the tow geometry data and used these models for micro-mechanical modelling of textile composites. In the published literature, authors mainly used idealised weave geometry ignoring the tow geometry variations during processing. The present paper demonstrates the impact of tensile, shear and transverse compression forces applied on dry fabrics during processing in relation to tow geometry. Experimental data was compared with theoretical predictions for a variety of weave topologies. Textile composite laminate properties have been estimated using modified laminate theory; these calculations demonstrated the impact of tow geometry changes during processing.