Mitigation of Sandwich Debond Damages under Influence of Impact and Low Temperatures for Robust Naval and Aircraft Structures
Abstract
In order for the US Navy to meet future challenges associated with both increased operations in the newly accessible arctic zone wit h surface vessels, as well as new improved and reliable aircrafts, light, robust and efficient naval and aircraft structures are nee ded, able to operate at both ambient and extreme cold environments combined with impact events with floating sea ice and harsh sea c onditions, or blunt impacts during operation, eg. from bird strikes. Composite sandwich structures have proven to be a very efficien t structural concept for naval and aircraft structures, but damage tolerance under extreme environments, for a range of sandwich mat erial configurations, is a key parameter to ensure sufficient robustness and structural integrity against service-loads and damage i ncidents. We propose a three-year program of basic research performed by the teams of PI and Co-PI at their respective institutions, DTU and UNIGE. The mechanics associated with the scenario of cold climate environmental loading, combined with dynamic impact event s and the subsequent fatigue damage propagation of face/core debonds (interface propagation and kinking) in typical naval and aircra ft sandwich structures will be established. Experimental testing, as well as analytical and numerical analysis, will be performed to fully understand and account for the complex interaction and evolution of the damage mechanisms involved. Based on the improved ins ight and knowledge about impact related damages, along with the associated face/core debond damage nucleation and subsequent fatigue growth, a new fracture mechanical crack kinking criteria will be proposed, implemented and used, through both analytical and numeri cal calculations, for the development of a novel interface propagation and kinking fatigue mitigation concept. The new mitigation co ncept can be integrated into future naval and aircraft sandwich structures using different configurations of sandwich face and core materials for improved robustness and damage tolerance in extreme environments, and will be demonstrated and qualified at both ambie nt and low temperature environmental conditions typical for arctic naval and high altitude aircraft operations respectively, and thr ough experimental testing and numerical analysis of the debond growth and kinking, underpinned by the new kinking criteria.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Oct 22, 2021
- Source ID
- N629092112048
Entities
People
- Christian Berggreen
Organizations
- Office of Naval Research
- Technical University of Denmark
- United States Navy