Maximising the long-term performance of composite structures, oroperation and sustainment, requires correct selection of materials, implementation of monitoring technologies, an in-depth understanding of in-service behaviour, development of maintenance processes and training of maintenance operators. Unique expertise in these fields places ACS Australia at the leading edge of new technology implementation.
We offer evaluation, specification and implementation of commercially available Structural Health Monitoring (SHM) sensors in practical composite structures, including repair and critical area monitoring and entire structure monitoring.
ACS Australia staff have a record of success in the innovation of repair of composite structures and developing composite repairs for metallic structures. Examples include the inspection and repair of damaged storage tanks, aircraft, helicopters and ships. We incorporate design for matched performance, in-situ manufacturing, quality assessment and certification in our repair solutions.
We provide technical advice on the most suitable type of repair to damaged composites and the rehabilitation of ageing infrastructure.
State-of-the-art equipment is available for the non-destructive evaluation (NDE) of damage in monolithic and sandwich composites.
We also have extensive knowledge of the application of functional coatings, and in-house developed surfacing technology, providing options for performance improvement of composites and development of multifunctional structures. Examples include integrated coatings for improved wear performance; reduced moisture uptake; integrated electrical conductivity and surface protection systems for fire protection; spray-on metal coatings and application technology for polymer surface coatings.
Structural Health Monitoring
The cost to operate and maintain critical infrastructure in industry sectors such as aerospace, oil & gas and civil runs into billions of dollars each year. However, many of the maintenance approaches used are inefficient, relying upon regimented practices that enforce costly downtime no matter whether the structure requires corrective action or not.
To overcome this issue ACS Australia staff and CRC-ACS participants have undertaken programs to develop and assess Structural Health Monitoring (SHM) technology that can be used to obtain a direct measurement of the health of a structure and thus allow more optimized, cost-effective maintenance practices to be implemented. This development of multifunctional “smart structures” is seen as a critical underpinning technology for future advances in many industry sectors.
Effort has been focused on the development and understanding of the monitoring capabilities in the key technologies of optical sensors, acousto-ultrasonics and comparative vacuum monitoring. ACS Australia staff have also built up a significant body of experience and knowledge on the issues of implementing these technologies into composite structures. This expertise has been recognized through the involvement of ACS Australia staff in several European collaborative programs to develop new SHM technology and overcome the issues of integrating SHM technology into aerospace applications.
Composites Fire Behaviour Modelling
Concern over fire behaviour has prevented many engineers considering composites as a viable solution in transport, building and industrial applications. In fact, composites can be specified for low flammability and good high temperature performance and the insulating properties of composites can be a considerable advantage in the prevention of fire spread, with consequential improvement in personnel and infrastructure safety. Understanding the behaviour of composites in fire is the key to extending the application of these materials.
As managers and principal researchers within a major international collaborative project, CRC-ACS has been instrumental in the development of fire behaviour modelling tools. These tools analyse structural integrity of composites during fire, allowing prediction of structure survival time and aiding correct specification of composites and associated insulation systems. The analysis methods have many applications including ship engine rooms and multi-storey buildings.
Through projects such as these, the staff of ACS Australia have already developed extensive expertise in the manufacture of low flammability composites and incorporation of surface protection systems. In combination with new-generation predictive capability, we are well placed to advise on the use of composites in fire-prone applications and to expand the employment of composites in these fields.
Repair of Structural Composites in Aerospace
With increased use of composites in highly loaded structures, repair technology needs to meet new demands of rapid design, fast application and robust performance.
Experts in repair technology from ACS Australia and the Defence Science and Technology Organisation (DSTO) led collaborative research inside CRC-ACS into solutions appropriate for highly loaded structures. The research focused on the development of innovative design approaches and rapid, low cost repair implementation technology.
Technology development encompassed software developments for the automatic generation of designs based on damage identification and structure performance, and predictive capabilities for repair failure. Repair procedures incorporating both hard patch and soft patch approaches were developed and demonstrated on aircraft components The technology leverages extensive understanding of adhesive joint mechanics and a thorough understanding of airworthiness certification requirements.
The technology developed in this programme is anticipated to bring tens of millions of dollars benefit to the defence and aircraft industries. Partner organisations in the aerospace and defence industry now have repair technology consistent with the application of composites in modern platforms. A range of other industries will benefit from increased performance and rapidity of structural composite repairs, allowing them to use composites in new applications with confidence.
Health Monitoring of Minehunter Composite Hulls
Minehunter vessels are predominantly manufactured from composite materials and are subjected to extreme loading through blast. Solutions were required to identify and monitor damage in critical structural components.
Experts in Structural Health Monitoring (SHM) and structural simulation led collaborative research inside CRC-ACS to develop a system capable of damage detection. The research focused on the development of optical fibre technology and the validation of its capabilities through structural test.
Extensive simulation of the structural behaviour of the critical hull-bulkhead joint was undertaken to identify the primary locations for failure under simulated blast conditions. A monitoring system consisting of optical fibre sensors embedded within the critical hull-bulkhead joint was produced that could detect the growth of damage within the joint without causing any detrimental effects to the performance of the joint through their presence.
The technology developed in this programme was demonstrated on representative maritime structures. Partner organisations in the defence industry now have access to SHM technology capable of implementation with large composite platforms. SHM technology is anticipated to bring tens of millions of dollars benefit to the defence industry through the development of more efficient maintenance practices. A range of other industries will benefit from decreased maintenance costs, opening new markets for composites applications.
- • Development of maintenance processes.
- • Training of maintenance operators.
- Structural Health Monitoring
- • Whole structure monitoring using sensor technology based on optical fibres (Bragg grating, Brillouin scattering) and piezoelectric transducers
- • Repair and critical area monitoring using fibre optic sensors and vacuum gallery sensors in critical areas including joints and early detection of repair degradation
- Repair and Rehabilitation Assessment
- • Non-destructive inspection (NDI) and survey of damage in monolithic and sandwich composites
- • Evaluation of criticality of damage; prediction of effect on performance and safety of a structure
- • Advice on suitable type of repair to damaged composites and rehabilitation of ageing composite structures
- Design of Repairs
- • Designs from reverse-engineered and OEM data
- • 2D/3D analysis
- • Impact simulation & failure modelling
- • Joint failure modelling for fastened composites and adhesives
- • Elasto-plastic and cohesive models for adhesive systems
- • Composite repairs for metallic structures
- New Repair Technology
- • Flush/stealth features
- • Rapid in-situ curing
- • Pre-manufacture of repair panels
- • Optimised implementation of scarf joints
- • Integration of strain- and vibration-based SHM technologies
- Materials and Testing
- • Full characterisation and testing of adhesive performance in repair
- • Manufacture and validation testing of full-scale prototypes
- • Development of coatings for improved performance