Development of a Computationally Efficient Fabric Model for Optimization of Gripper Trajectories in Automated Composite Draping

TL;DR

This paper introduces a fast, 2D catenary-based fabric model for optimizing gripper trajectories in automated composite draping, aiming to prevent wrinkles and misplacement during fabric placement.

Contribution

A novel computationally efficient fabric model based on 2D catenaries is developed for optimizing gripper trajectories in automated draping systems.

Findings

Model accurately predicts fabric displacement fields.

Model is computationally efficient for optimization tasks.

Effective in avoiding fabric misplacement and wrinkles.

Abstract

An automated prepreg fabric draping system is being developed which consists of an array of actuated grippers. It has the ability to pick up a fabric ply and place it onto a double-curved mold surface. A previous research effort based on a nonlinear Finite Element model showed that the movements of the grippers should be chosen carefully to avoid misplacement and induce of wrinkles in the draped configuration. Thus, the present study seeks to develop a computationally efficient model of the mechanical behavior of a fabric based on 2D catenaries which can be used for optimization of the gripper trajectories. The model includes bending stiffness, large deflections, large ply shear and a simple contact formulation. The model is found to be quick to evaluate and gives very reasonable predictions of the displacement field.