Periodic Reporting for period 1 - INFORM (Interlaminar Fracture of Fiber-Hybrid Composite Laminates: A Multiscale Approach)
Período documentado: 2023-12-01 hasta 2025-11-30
Carbon-fibre-reinforced polymer (CFRP) composites are essential for the next generation of high-performance lightweight structures, particularly in the aerospace and automotive sectors. However, these materials are prone to delamination, a failure mode where the composite layers separate. Predicting and preventing this is critical, as current engineering practices often lead to heavy 'over-designed' components to ensure safety.
The INFORM project was motivated by the need to understand how these internal cracks grow and migrate within multidirectional, thin-ply composites. The overall objective was to move from trial-and-error testing toward a reliable multiscale approach that combines advanced mathematical modelling with high-resolution 3D imaging. By establishing the technical foundations for more damage-tolerant designs, the project contributes directly to the EU’s 2030 climate objectives. Lighter composite structures enable significant fuel savings and a lower carbon footprint in transportation, addressing key environmental and economic needs within the EU’s 624 M€ composite market.
The INFORM project was motivated by the need to understand how these internal cracks grow and migrate within multidirectional, thin-ply composites. The overall objective was to move from trial-and-error testing toward a reliable multiscale approach that combines advanced mathematical modelling with high-resolution 3D imaging. By establishing the technical foundations for more damage-tolerant designs, the project contributes directly to the EU’s 2030 climate objectives. Lighter composite structures enable significant fuel savings and a lower carbon footprint in transportation, addressing key environmental and economic needs within the EU’s 624 M€ composite market.
The INFORM project successfully integrated high-fidelity numerical simulations with pioneering experimental validation. A major achievement was the development of a custom, X-ray transparent mechanical testing rig. This allowed researchers, for the first time, to observe the 3D development of internal shear-driven cracks (mode II delamination) in situ using X-ray computed tomography (CT).
Key technical achievements include:
- Successful capture of delamination fronts and delamination migration events within the material bulk at a micro-scale resolution of 3.5 μm.
- Identification of complex 'zig-zag' fracture patterns in angle-ply laminates, providing volumetric evidence of how local microstructures dictate material failure.
- The project developed and validated a numerical design tool capable of predicting these failure paths with high accuracy, benchmarking them against real-time experimental data.
Key technical achievements include:
- Successful capture of delamination fronts and delamination migration events within the material bulk at a micro-scale resolution of 3.5 μm.
- Identification of complex 'zig-zag' fracture patterns in angle-ply laminates, providing volumetric evidence of how local microstructures dictate material failure.
- The project developed and validated a numerical design tool capable of predicting these failure paths with high accuracy, benchmarking them against real-time experimental data.
INFORM moved beyond the current state of the art by challenging the 2D assumptions of existing international standards (such as ASTM D7905) and conventional edge-monitoring techniques. While traditional methods only monitor the edges of a specimen, our in situ CT approach proved that critical damage often occurs internally before it becomes visible on the surface.
The project proposed a new standardised protocol for 3D characterisation of shear-driven fracture. The potential impact is a shift toward 'virtual testing', where high-fidelity models reduce the need for expensive and time-consuming physical experiments. To ensure further uptake, future work will focus on integrating these 3D imaging datasets into industrial certification frameworks. This success has already secured follow-up funding for the FWO PATTERN project and supported the researcher’s transition to a faculty position at Politecnico di Milano.
The project proposed a new standardised protocol for 3D characterisation of shear-driven fracture. The potential impact is a shift toward 'virtual testing', where high-fidelity models reduce the need for expensive and time-consuming physical experiments. To ensure further uptake, future work will focus on integrating these 3D imaging datasets into industrial certification frameworks. This success has already secured follow-up funding for the FWO PATTERN project and supported the researcher’s transition to a faculty position at Politecnico di Milano.