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OPTIMISING STRUCTURAL FIBRE COMPOSITES BY HYBRIDISATION

Objective

THE AIM OF THE PROJECT IS TO PRODUCE COST EFFECTIVE HIGH PERFORMANCE POLYMER COMPOSITES BY JUDICIOUS REINFORCEMENT AND MIXING (HYBRIDIZATION )0) OF BOTHHIGH AND LOW PERFORMANCE FIBRES IN THE SAME MATRIX SYSTEM.TO ACHIEVE THIS OBJECTIVE IT IS PROPOSED TO FABRICATE A SYSTEMATIC SERIES OF MIXED FIBRE(E-GLASS,CARBON,ARAMID,ETC.) COMPOSITES BASED SEPARATELY ON BOTH THERMOPLASTIC AND THERMOSETTING MATRICES.DETAILED STUDIES WILL THEN BE CARRIED OUT TO INVESTIGATE THE MECHANISMS BY WHICH LOADS ARE TRANSFERRED BETWEEN FIBRES AND MATRIX UNDER COMPRESSIVE,TENSILE AND FLEXURAL LOADING.THE FAILURE PROCESSES WILL BE QUANTIFIED BY SURFACE FRACTURE ANALYSIS,ACOUSTIC EMISSION,AND ELECTRONIC SPECKLE PATTERN INTERFEROMETRY TECHNIQUES.,ETC.THISWILL ALLOW THE DEVELOPMENT OF MATHEMATICAL MODELS TO PREDICT MECHANICAL BEHAVIOUR.THUS IN THE LONG TERM IT IS HOPED THAT THE PROJECT WILL PROVIDE DATA TO IDENTIFY NOVEL COST COMPETITIVE LIGHTWEIGHT HYBRID MATERIALS WITH IMPROVED BUCKLING RESISTANCE AND DAMAGE TOLERANCE.
The aim of the project is to produce cost effective high performance polymer composites by judicious reinforcement and mixing (hybridisation) of both high performance and low performance fibres in the same matrix system. To achieve this objective it is proposed to fabricate a systematic series of mixed fibre (E-glass, carbon, aramid, etc) composites based separately on both thermoplastic matrices and thermosetting matrices. Detailed studies will then be carried out to investigate the mechanisms by which loads are transferred between fibres and matrix under compressive, tensile and flexural loading. The failure processes will be quantified by surface fracture analysis, acoustic emission, and electronic speckle pattern interferometry techniques, etc. This will allow the development of mathematical models to predict mechanical behaviour. Thus in the long term it is hoped that the project will provide data to identify novel cost competitive lightweight hybrid materials with improved buckling resistance and damage tolerance.

Pressure/temperature conditions have been optimised for carbon fibre reinforced polypropylene composite production and glass fibre reinforced polypropylene composite production so that ply misalignment is minimised.

At this stage of reporting, all partners are actively involved in those aspects of the mechanical testing subprogrammes assigned to them. Thus data is now available on tensile, flexure, compression and falling weight impact behaviour. Early impressions are that some of the sample combinations are exhibiting synergistic hybrid effects in the sense that certain mechanical properties are not necessarily predictable in terms of the mechanical performance of their components (weighted in terms of their volume fractions present in the composite). Predictive behaviour models and graphs produced to represent falling weight impact behaviour, however, look very promising and initial examples are available for comparison purposes. Future repor ts will fully disseminate all the mechanical data and additional evidence provided by acoustic emission analyses and detailed fractographic examination will be used to refine and develop behavioural models and the prediction of optimum material combinations.
CURRENTLY,IN THIS FIRST STAGE OF THE PROJECT,THE PARTNERS HAVE BEEN REFINING COMPOSITE FABRICATION TECHNIQUES,AND PRODUCING THE FIRST SERIES OF SAMPLES FOR MECHANOICAL TESTING.TO THESE ENDS,PRESSURE/TEMPERATURE CONDITIONS HAVE BEEN OPTIMIZED FOR CARBON AND GLASS FIBRE REINFORCED POLYPROPYLENE COMPOSITE PRODUCTION SO THAT PLY MISALIGNMENT IS MINIMIZED;.SIMILARLY,A FILAMENT WINDING MACHINE WITH TWO CONTROL AXESHAS BEEN MODIFIED TO ALLOW PRODUCTION OF THERMOSETTING COMPOSITES WITH SYSTEMATICALLY VARYING LAY-UP GEOMETRIES AND VOLUME FRACTIONS.INITIAL COMMISSIONING TRIALS ON ACOUSTIC EMISSION EQUIPMENT HAVE SUCCESSFULLY PROGRESSED TO MODIFYING SOUND TRANSDUCERS SO THAT THEY CAN BE FITTED ON CRAG 400 COMPRESSION RIG SPECIMENS.THE COMPUTER MODELLING WORK AS BEEN STARTED WITH THE SOFTWARE FOR A DATA-BANK PROGRAMME WELL ADVANCED.

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

LOUGHBOROUGH UNIVERSITY
Address
Ashby Road
LE11 3TU Loughborough
United Kingdom

Participants (3)

Centre Technique des Industries Mécaniques (CETIM)
France
Address
52 Avenue Félix Louat
60304 Senlis
FOUNDATION FOR TECHNICAL AND INDUSTRIAL RESEARCH AT THE NORWEGIAN INSTITUTE OF TECHNOLOGY
Norway
Address
1 D,strindveien 4
7465 Trondheim
PRODUCTION ENGINEERING RESEARCH ASSOCIATION - PERA
United Kingdom
Address
Technology Centre, Nottingham Road
LE13 0PB Melton Mowbray