The Operations and Sustainment program of the CRC-ACS (Program 3) focuses upon the development of repair and structural health monitoring technology suitable for the Aerospace and Oil & Gas industry sectors.

Across many industry sectors the costs associated with the maintenance and repair of major infrastructure is becoming an increasingly significant aspect of business.  Whether it is an aircraft constructed from composites and light-weight metals or an oil platform with an ageing steel construction, structural failures can result in critical safety and environmental situations as well as millions of dollars lost due the unexpected downtime.  The focus of the Operations and Sustainment program is to provide technologies for maintaining the new generation of composite aircraft, for extending the life of existing steel infrastructure, and for prevention of critical failures in the Oil & Gas industry.  The program will support a more efficient whole-of-life approach to the implementation of composites.  The program consists of three projects, all of which are further developing technologies and capabilities developed in the previous CRC-ACS research program and applying it across different industry sectors.

While the usage of composites in aircraft is increasing dramatically, particularly in primary structure, the technology to rapidly and efficiently repair such structures lags behind.  Previous CRC-ACS research developed extensive expertise in composite repair technology, however repairs currently used within the aircraft industry are generally based upon basic methods of metallic structure repair or, for bonded composite repairs, are not certified for use on primary structure.  P3.1 – Robust Composite Repairs aims to advance the certification of bonded repairs to primary composite aircraft structure through the development of a certification framework, built on test data, that incorporates: a validated analysis methodology; improved materials and processes; and enhanced inspection and monitoring procedures.

A focus of the project is to identify and develop best practice materials and processes for composite repair linked with repair inspection or monitoring approaches that will help overcome some of the certification concerns of bonded repairs.  Improved repair design and analysis methodologies will also be developed that will address the mechanical performance requirements of the repair.  The final aspect of this project is the development of a test framework that will generate relevant design data and demonstrate the required repair performance, all relevant to the certification requirements for bonded composite repairs (see Figure 1).

The project is lead by Dr Andrew Gunnion. Participants are; Advanced Composite Structures Australia Pty Ltd, Bishop GmbH, Defence Science and Technology Organisation, Deutsches Zentrum für Luft- und Raumfahrt e.V., EADS Australia Pacific Pty Ltd, Monash University, MSC.Software Australia Pty Ltd, Pacific Engineering Systems International Pty Ltd, RMIT University and the University of Queensland.

Figure 1: Illustration of bond proof test concept, showing bonded patch repair, surrounded by satellite "bond repair coupons", which are periodically tested in shear throughout the repair lifetime

Repair technology is even more critical for major, non-aerospace infrastructure.  Large, ageing platforms in remote locations require the development of in-field, rapid, low-cost repair technologies that will minimise expensive downtime (the cost in lost revenue from downtime can be up to USD 5M per day).  The extensive composite repair and rapid design/manufacture experience that has been developed within the previous CRC-ACS research program and participant organisations will be adapted for the development of repair and rehabilitation expertise for ageing infrastructure.  P3.2 – Structure Repair and Rehabilitation aims to develop certification-ready technologies for the repair and rehabilitation of steel pipeline systems, through the development of engineering analysis methodologies, the implementation of novel liner systems as part of an integrated composite repair solution, and the verification of integrated repair solution performance in the operational environment (see Figure 2).

With the application focus of steel pipelines, the project will develop analysis methods compatible with “Limit State” design procedures which will enable rapid design of composite repair solutions.  Innovative materials and implementation technologies will be identified and developed along with an improved understanding of repair durability in the expected service environments.  An assessment will be undertaken of repair inspection techniques and trials of the developments within the project will be carried out in conjunction with PETRONAS.

The project is lead by Dr Paul Falzon.  Participants are; Advanced Composite Structures Australia Pty Ltd, Brenco Aerospace Pty Ltd, MSC.Software Australia Pty Ltd, Pacific Engineering Systems International Pty Ltd, PETRONAS Research Sdn Bhd, PLASMATE JSC, Specialty Coatings (Aust) Pty Ltd, Structural Monitoring Systems Ltd, University of Sydney, Unique Solution Partners Pty Ltd, University of New South Wales, University of Newcastle upon Tyne, University of Queensland and the University of Southern Queensland.

Figure 2: Prototype spool hydrostatic pressure test

Structural Health Monitoring (SHM) technology is relevant to multiple industries. It provides the basis for real-time health monitoring of critical structures and implementation of Condition Based Maintenance approaches, significantly reducing costs for the operation and support of structures.  Within previous research programs CRC-ACS has developed significant expertise in evaluating and developing SHM technology in composites. A major barrier to adoption of SHM technology is the development of robust systems for practical diagnosis of damage signals.  P3.3 – Systems Development for SHM aims to develop and validate SHM systems for composite applications on selected platforms in the Oil, Gas & Petrochemical (OGP), Aerospace and Defence industry sectors.

This project has the three principle end-users of the CRC-ACS as participants (DSTO, EADS & PETRONAS) and therefore has three industry applications being used as the focus for the SHM systems development.  However, in all three cases the project activity will focus upon the identification and development of technology suitable for the specific application together with the certification guidelines for its implementation.  A major challenge to be addressed during the project is the development of methodologies for system design through simulation and damage diagnostics and prognostics.  The SHM systems for each of the applications will have their capabilities assessed and validated through laboratory and field trials (see Figure 3).

This project is led by Dr Michael Bannister.  Participants are; Advanced Composite Structures Australia Pty Ltd, Bishop GmbH, Defence Science and Technology Organisation, EADS Australia Pacific Pty Ltd, Monash University, MSC.Software Australia Pty Ltd, Pacific Engineering Systems International Pty Ltd, PETRONAS Research Sdn Bhd, RMIT University, University of Queensland, University of Southern Queensland and the University of Bordeaux.

Figure 3: Strain field on the surface of a composite overwrap repair due to the presence of damage in the steel pipeline.