Measurements for Materials Systems (MMS)

MMS13 – Assessment and Criticality of Defects and Damage in Materials Systems

MMS15 – Interactive Knowledge Base (IKB) on NDE and Design of Composites

Minutes of 4^th Industrial Advisory Group Meeting

Thursday 15^th January 2004

Zeta Room, AEA Technology, Culham Science Centre

Attendees

Gordon Bishop NetComposites Richard Lee AEAT

John Cantrill VT–Halmatic Bob Lewin Rolls-Royce

Graham Sims (NPL) Rod Martin MERL

Gordon Drummond Imes Ltd Nigel Evans Insys

Andreas Obst ESA Mike Gower NPL

Sue Panteny Faraday Advance Roger Gregory LTI

Mark Stone AEAT Martin Wall AEAT

Graeme Hughes HSE Steve Wyatt Quo-Tec Ltd

Joan Cocksedge DTI Anne Birt QinetiQ

Apologies

Roger Davidson CTG, Peter Frewer (Anvil Innovations), Raman Patel (HSE), Steve Austen (RNLI), David Lindsay and Peter Hills (RAF St. Athan), Simon Frost (AEAT), Shayz Ikram (L.O.T. – Oriel Ltd.), Sam Luke Mouchel-Parkman, Keith McClaughlin Advanced-NDT, Fadhil Habib BAE Systems

1. Welcome and introduction

Richard Lee (RL) welcomed members of the joint IAG to AEA Technology for the fourth MMS13/15 IAG meeting. He then explained that the intention was to have an independent chairman for the IAG meetings and that Graham Sims (GS) had agreed to chair the morning session (N.B. the project partners are looking for a volunteer to chair the next meeting). GS went through the meeting agenda and then asked if anyone had any issues with the minutes from the last IAG meeting. The minutes were approved. GS asked if members would briefly introduce themselves to the group.

2. Project progress

2.1 MMS13

Mike Gower (MG) gave a brief overview of the MMS13 objectives, project structure and current status/progress of the live tasks. He then went on to describe some of the experimental test work that had been undertaken as part of the materials characterisation activities of Task 2. Firstly, MG gave details on the tests that had been completed so far for characterising the two resin infused GRP materials supplied by VT/Halmatic. He reported that all panels had been received by NPL and that testing would be completed (including the Mode I and II fracture toughness tests) by the end of February ’04. The results of the material characterisation work will be presented in full at the next IAG meeting in July ’04. MG then went on to describe tests that had been carried out on two ultra high modulus (UHM) CFRP materials used for bonded over-wrap repairs for stiffening and/or repair of ageing bridge structures. The materials are also being used as a case study in MMS6 ‘Classification and Assessment of Composite Material Systems for use in Civil Infrastructure’. Within MMS13, work to date has looked at providing a suitable methodology for the measurement of tensile modulus. Finally MG gave an overview of the progress on the materials testing aspects of Task 5 – Defect Criticality. He said that the material data requirements for the 3 level assessment approach adopted by MMS13 had been defined for each level, and that a report had been produced providing guidance on appropriate test methods/procedures for generating such data.

Richard Lee (RL) presented work that had been carried out on Task 3 – Non-destructive evaluation assessment.

Mark Stone (MS) updated members on the progress that had been made on Task 5 – Assessment of defect criticality. MS reported that most defect types within composite material systems could broadly be characterised as being similar to either delaminations or matrix microcracking. He stated that his assessment of defect criticality had considered these two types of defect only and that a three level approach had been established for criticality assessment. The first level involved a simple assessment, which may be highly conservative, whilst the third level assessment provided for a highly detailed analysis resulting in minimum conservatism.

2.2 MMS15

Martin Wall (MW) gave an overview of the IKB on NDE of composites (MMS15). He began by providing a review of some of the key features of the IKB and then gave details of progress made since the last meeting and on the shared notice board for MMS13/15. From the notice board, project reports, minutes from meetings and presentations can be viewed/downloaded. The MMS15 website address is www.mms15.com. There is now an IAG member’s only area (password protected) on the notice board, where draft reports and confidential information can be accessed.

The presentation showed examples of the current version of the IKB. In addition to the publicly accessible beta version on the NetComposites site www.netcomposites.com/ikb there is a new “development” version accessible from the members area of the MMS15 website. This enables information to be uploaded and reviewed by IAG members, which is not yet finalised for public access.

Information was given on a number of recent case studies including an assessment of laser shearography on GRP train cabs for Porterbrook Leasing Ltd. IAG members were asked to review their recent inspection activities and see if any trials or information would be suitable for inclusion in the IKB. Action IAG members.

A demonstration was given of probability of detection (PoD) models for composite materials originally developed for the European Space Agency. The software covers ultrasonic and radiographic inspection producing simulated NDE data and probability of detection curves. A cost benefit model for inspection, known as the Inspection Value Method (IVM), was also demonstrated. Both models could be valuable for decision making on inspection of composite materials. It was planned to make these accessible in some form through the IKB.

A successful mid-term review was carried out by Quotec and DTI during a break-out session in the early afternoon attended by Martin Wall (MW), Gordon Bishop (GB) and Anne Birt (AB).

3. Related presentations from industrial partners

After lunch, RL introduced a series of presentations from IAG members. The purpose of the afternoon talks was to provide a chance for members to present work that was related to the MMS13 and 15 projects and to raise issues that were of current concern/importance to industry.

Rod Martin (RM, MERL) spoke about the Mode I delamination testing particularly for external threats to rotorcraft structures. He presented some of the work that he intends to carry out on the case study materials.

Andreas Obst (AO, ESA) presented work on the damage modelling requirements and NDT techniques that are currently used within ESA. He provided details on the previous programmes and his presentation is attached,

Steve Burch (SB, AEA Technology) described the background to the Harwell Offshore Inspection Service (HOIS). Further details are available on the web www.hois2000.com.

Roger Gregory (RG, LTI) provided details on laser shearography and illustrated the range of defects that can be detected using this technique through a series of case studies that his organisation had undertaken. This included a high-speed 125 composite railway cab and a high performance sailing vessel.

Presentations will be available for download in the members area of the MMS15 website. Please email info@mms15.com if you do not have access details.

The future 3-year MMP programme is expected to start later in 2004. Project F12 is concerned with the development of test methods for determining the criticality of defects in composite materials systems under long-term loading. This is expected to start in April 2004 at NPL.

5. Date of next meeting

The next joint MMS13/15 IAG meeting will be held on the 15^th of July 2004 at NPL. An agenda will be sent out to members in due course.