Introduction to Draping Simulation with LS-DYNA

Increasing demands for light-weight structures have made continuous fiber reinforced composite to a widely used material in different industries. Due to their typical, strongly pronounced anisotropy the final properties of the parts are dominated by the fiber orientation found in the structure and, thus, by the manufacturing process.

A draping process step defines the fiber orientation in most of the manufacturing processes used today. This particular step includes the forming of a textile that is either dry or only coated by a fluid-like matrix. In order to analyze producability of a part or to predict folds in or the properties of a part in an early stage of the design-process, it is of crucial importance to include the draping in a numerical simulation. Depending on the used matrix material the temperature distribution cannot be neglected in the analysis.

This seminar introduces material models available in LS-DYNA that are tailored for draping and the modeling techniques those are based on. Furthermore, necessary input keyword cards and settings for the process simulation are presented. In particular, the possibilities of a coupled thermal-mechanical simulation are discussed in detail.

The results of the draping step have to be transferred to following process stages or the structure analysis in order to close the virtual process chain. In this context, the mapping tool ENVYO® is briefly presented.

Contents

• Introduction to composite materials
• Explanation of anisotropy and direction definitions
• Material modelling
  • Modeling approaches for UD, NCF and woven fabrics
  • Material models in LS-DYNA
• Process simulation
  • Necessary input cards
  • Contact settings
• Simulation of coupled thermal-mechanical processes
  • Introduction to the thermal solve in LS-DYNA
  • Specifics of a coupled forming simulation
• Closed simulation process chain using ENVYO®