With the increasing use of composites in critical applications with long service lives, it is desirable to integrate some level of smart functionality into the material.
A smart material is defined as a material which has some additional functionality to its primary (usually structural) purpose. Typically these additional functions fall into the categories of actuation, sensing or healing.
The CSIC is active in the field of smart composite materials with active projects to create materials with the ability to both sense damage and degradation and to self-heal (or at least ameliorate) the damage. In particular our projects are in the following areas:
- Detection of damage in carbon-fibre composites by electrical means.
- Detection of damage in glass-fibre composites by optical means.
- Chemical condition monitoring of polymer matrices.
- Solid state healing of damage to composites by modified matrices.
- Healing of damage to composites by thermally reversible network polymers.
The use of computer modelling to verify design is now virtually ubiquitous throughout many industries. However despite being commonplace, modelling of engineering applications is still complex, and costly mistakes are easily made if computing power is thrown at a problem without the accompanying brain power.
Composites are highly complex materials, being anisotropic, non-linear and strain rate sensitive. When these materials are combined with complex boundary and load conditions the result is often a modeller's worst nightmare.
The CSIC specialises in the modelling of composites, including in complex load cases such as blast, ballistic impact loading or fatigue. We also have expertise in polymer chemistry so are able to model everything from the level of molecules up to a full structure exposed to an explosion. Current project areas in this field include:
- Modelling of bonded and bolted joints.
- Modelling the effects of blast on composite structures, and how to minimise damage.
- Modelling the effects of ballistic impact, and how to minimise penetration.
Lower environmental impact materials
Environmental considerations are increasingly becoming a deciding factor in engineering design, and the need for improved materials with lower environmental impact is a major driver in materials research.
Composites have both drawbacks and advantages in environmental terms. Structures produced from composites are inherently lighter than those from other materials, meaning that fuel (and associated environmental) savings can be expected when composites are used in any transport sector. The CSIC is a world leader in conducting life cycle analysis on composite materials.
However the feedstocks used to produce polymer composites are usually derived from oil, which makes them unsustainable and hard to dispose of. The CSIC conducts research in polymers and composites which are bio-derived, bio-degradable and/or recycled, making them sustainable and environmentally disposable. Current project areas in this field include:
- Improvement of bio-polymers for use in packaging.
- Improvement of recycled polymers for use in rail infrastructure.
- The applications and properties of recycled carbon-fibres.
- The application of Life Cycle Analysis to a variety of real world cases, including the Boeing 787 Dreamliner aircraft.
The CSIC applies various high technology solutions to composite materials. We have within our own labs a variety of high technology devices and instruments, and are able to collaborate with other departments within the University of Sheffield to access an even wider variety of instruments and technologies at nano, micro meso and macro scale. Current project areas in this field include:
- Optimisation of the fibre-matrix interface, including the use of plasma based treatments.
- Glass ceramic fibre composites.
- New hybrid materials.
- Nano-optimised materials.