Damage mechanisms and tolerance in thick skin sandwich structures

Purpose and goal

The project has investigated and proven clear relations between impact damage on composite structures and its influence on residual strength. Such knowledge is a key element for certifying engines where composite components may be subject to foreign object impact. The results and conclusions have international news value within academic research and support GKNs ongoing work to develop technology for more efficient engines with reduced fuel consumption.

Expected results and effects

Besides appreciably increasing the knowledge for the involved parties, the project has resulted in several scientific publications; two conference papers, two journal papers (1 published, 1 in review) and additionally two manuscripts for journal papers. A novel test equipment has been developed, with a patent pending (2017). Several new discoveries and conclusions were made in connection to the performed testing. These results are partly generic and judged to be of interest and useful in a broader range of applications than only aero engine design.

Planned approach and implementation

Trough comprehensive experimental work and simulation, damage resistanse of sandwich materials with thick composite skins of carbon fiber reinforced plastic and polymere foam core was studied. The effect from various impact energies on damage size and severeness was investigated through experiments and influence on the residual strength was determined by compression and bending tests. Parallel to the experimental testing, simulation models of the impact event were generated showing an overall good correlation with the experimental results.