INTRODUCTION

ELADINE addresses topic WP B-1.2 of the AIRFRAME [SAT] in the Spring-in prediction capability for large integral composite material wing box of a 19 passenger commuter aircraft.

1. Objectives 

ELADINE aims to implement a numerical tool that can reduce the recurring costs of low-volume composite manufacturing of airframe parts and, with this benefit, the reducing of the overall manufacturing effort and carbon emissions through three converging manners:

1. The design and geometry compensation of the tooling itself as an essentially integrated phase of the manufacturing cycle. ELADINE focuses specifically on composite tooling and the overall behavior of the tools and the parts during the entire curing process;

2. Mastering the capacity of controlling the manufacturing process in order for large aero-structures and their assemblies not to fail the tolerance constraints;

3. Optimizing the number of coupons and specimen testing before manufacturing of aero-structures, by a thorough understanding of thermal, chemical and mechanical behavior of tooling and parts, tool-part interaction and resin flow.

ELADINE will demonstrate the ability of accurately predicting spring-in on a complex aero-structure for both LRI and prepreg manufacturing.

A numerical tool for the spring-in prediction of primary structural components brings remarkable benefits:

2.  Ambition

The main outcome of ELADINE project is a method for the analysis and simulation of the spring-in phenomena for integral structures based on detailed design information, materials properties and process definition. The numerical tool will be validated for two materials systems and manufacturing processes chosen in the OPTICOMS Project, but the development of this tool will not be limited exclusively to these materials and processes.

1.  Coupons definition

ELADINE project will focus on the structural analysis of the curing cycle in different types of specimens. Each specimen will be in close connection with the parts that will result from the tooling system in the FITCoW project. The results obtained in ELADINE will influence the final geometry of the tooling system in FITCoW, allowing for a good overall tolerance of the manufactured parts.

Different types of specimens will be studied to understand the evolution of the influence of each parameter in the curing process. The specimens will gradually increase in complexity and the trials are based on an in-crescendo of laminate. Firstly, PHASE 0 will study 2D simple laminates of resin, 1-layer composite, and finally n-layers composite. PHASE 1 will study more complex 3D coupons.

ELADINE will study the deformation of both Liquid Resin Infusion
parts and prepreg-manufactured parts for identical geometries

2. Process monitoring

Two kinds of sensors, Fiber Optic and Dielectric, will be used in this project for the process monitoring. The fiber optic sensors selected for ELADINE project are Fiber Bragg Gratings (FBG), because of the multiplexing power and high resolution. The sensors deployed in the data collection process are:

·  SFBG (strain FBG sensor)

·  TFBG (temperature FBG sensor)

·  DCS (dielectric curing sensor)

The ELADINE numerical tool will be employed to calculate the spring-in geometry compensation of the FITCoW tooling that will manufacture a 7-meter composite integral wing-box.

The numerical tool aims at predicting the spring-in phenomenon by Coupled Component Interaction Approach, modelling and simulating all the parameters that influence the final geometry of the parts.