This project will combine aspects of materials science and high strain-rate / impact research to investigate composite material response to hypervelocity impacts. This field is becoming ever more relevant as both vehicles (including aircraft and space platforms) and weapon systems move into the hypervelocity regime.
The drive to reduce mass and therefore enhance efficiency in the aerospace industry has pushed composite materials to the fore for both aircraft and space-relevant structures. Such systems face numerous threats ranging from foreign objects encountered on the runway through hail, bird-strikes, on-orbit debris for spacecraft and even man-made threats such as anti-aircraft missiles. This project therefore aims to investigate composite failure modes following impacts of projectiles travelling at hypervelocities, i.e. 2 km/s+, an area where there is currently a significant paucity of information in the literature.
This study will investigate the core assumption that composite damage in the hypervelocity regime continues to follow a velocity / strain-rate like progression – something which is currently known to occur in the ballistic regime only. Key aims include:
- Development and demonstration of an experimental approach to interrogate composite damage evolution in the hypervelocity regime
- Provision of evidence of the nature of damage evolution in composite materials at velocities >2 km/s – relevant to space and hypervelocity threat scenarios
- Initial establishment (both for the core industrial sponsor and aligned with a wider Cranfield-driven activity focused on hypervelocity impact driven risk assessment) of the kernel of a database of material response at elevated velocities / strain-rates
- Establishment of the importance of composite (CFRP) lay-up on material response in the hypervelocity regime, approaching and exceeding the hydrodynamic threshold
- Providing insight into the influence of projectile properties on hypervelocity impact on composites
- Establishing a numerical simulation capability for composite materials in extreme conditions using commercially available tools
This project will primarily be undertaken at Cranfield University’s Shrivenham Campus (the School of Defence and Security), with additional research being undertaken on a campaign basis at the partner institution (Birmingham University) as well as with the industrial sponsor (QinetiQ).
Insight into hypervelocity impact / failure modes from this research will provide significant benefits to both the defence and civil sectors. For example, enhanced understanding of such behaviour has the potential to facilitate improved resistance to bird strikes for aircraft structures, as well as inform more effective development of space-relevant structures and shielding. Linking experimental and numerical behaviour / validating the same will provide a unique predictive capability which will, more widely, underpin the on-going novel research into extreme environments at both Cranfield and Birmingham.
This project is linked to a wider collaboration between Cranfield and Birmingham exploring material systems under extreme conditions (the Consortium for Organotypic Research on Ageing and Microgravity: www.birmingham.ac.uk/extreme-environments.
As part of this, the successful candidate will have access to a unique suite of compressed and powder-gas launchers, including the highest velocity gas-gun currently operating in the UK (capable of accelerating projectiles up-to 8 km/s / 17,900 mph) as well as high level materials analysis capabilities based at Birmingham. In addition, close collaboration with the industrial sponsor will ensure that the research is focused at and beyond the cutting edge of current knowledge.
This PhD will provide a unique grounding in the high strain-rate and impact fields, as well as links into both high profile Universities and a defence prime. Skills and knowledge will have applications in areas including materials science, aerospace and defence.