Draping simulations of carbon/epoxy fabric prepregs using a non-orthogonal constitutive model considering bending behavior

In this study, a draping simulation technique that can reflect the mechanical behavior of uncured woven fabric prepregs, including bending characteristics, was implemented using non-orthogonal constitutive VUMAT code and a lay-up shell model. The basic mechanical properties of uncured woven fabric prepregs were accurately obtained through uniaxial tensile, picture frame shear, and cantilever bending tests for the draping simulation. The major moduli of the uncured fabric prepregs were derived from semi-empirical formulae, and the mechanical properties of the lay-up shell element were estimated by using the rule of mixture for all layers. Using the proposed simulation technique, the drapability and wrinkle generation qualities of a fabric composite structure with a complex geometry, i.e., an egg-box panel, were estimated according to the initial draping orientation (30 degrees and 45 degrees), and the simulation results were experimentally validated.

Automated summary

This study developed a draping simulation technique that can reflect the mechanical behavior of uncured woven fabric prepregs, and accurately obtained the basic mechanical properties through tests and simulations, for evaluating and validating fabric composite structures.