No abstract

Hybrid laminates typically consist of alternate layers of fibre-reinforced polymer and aluminium alloy. Developed primarily for fatigue critical aerospace applications, the hybrid laminates are orthotropic materials with lower density and higher strength compared to the aluminium alloy monolith. One of the damage mechanisms of particular interest is that of fatigue crack growth, which for hybrid laminates is a relatively complex process that includes a combination of delamination and fibre bridging. To facilitate the development of a unified model for both crack and damage growth processes, a remote sensing system, reliant upon fibre optic sensor technology, has been utilised to monitor strain within the composite layer. The fibre optic system, with capacity for sub microstrain resolution, combines time domain multiplexing with line switching to monitor continuously an array of Bragg grating sensors. Herein are detailed the findings from a study performed using an array of 40 sensors distributed across a small area of a test piece containing a fatigue crack initiated at a through-thickness fastener hole. Together with details of system operation, sensor measurements of the strain profiles associated with the developing delamination zone are reported.

As part of a project to optimise hybrid laminates for resistance to fatigue failure, arrays of fibre Bragg gratings are being used to monitor small-scale strain perturbations in composite materials. A remote multiplexed sensing system with 40 remote sensing sites using fibre optic technology, has been developed to monitor the strain field developed across the composite lamina of a hybrid laminate in the vicinity of a fatigue crack. Developed primarily for fatigue-critical aerospace applications, i.e. fuselage and lower wing skins, the hybrid laminates are orthotropic materials having lower density and higher strength than a simple alloy monolith without reinforcement. Fatigue crack growth in hybrid laminates is a complex process that involves a combination of delamination and fibre bridging. The fibre optic system has been applied to the problem of characterising delamination zone development about a fatigue crack, initiated at a through-thickness fastener hole.

With ICT Standards playing a key role in support of research and development in many disciplines, the European Commission Institute for Energy and Transport is keen to promote the development and adoption of ICT Standards for engineering data. In this respect, its MatDB Online facility is a Standards-based system for preserving, managing, and exchanging engineering materials test data. While MatDB Online has evolved over more than 30 years to incorporate the latest innovations in data preservation and exchange, such as XML-based data transfer and data citation using digital object identifiers, it continues to rely on a robust data model developed more than 30 years ago through the joint efforts of the National Research Institute for Metals

Materials database interoperability has been of great interest in recent years for information exchange in support of research and development (R&D). In response to data and knowledge sharing needs of the Gen IV International Forum (GIF) for global collaboration in nuclear energy R&D, the European Commission JRC Institute for Energy and Transport (JRC-IET) and the Oak Ridge National Laboratory (ORNL) established a materials database interoperability project that developed techniques for automated materials data exchange between systems hosted at the two institutes—MatDB Online at JRC-IET and the Gen IV Materials Handbook at ORNL, respectively. The work to enable automated exchange of data between the two systems leveraged the XML data import and export functionalities of both systems in combination with recently developed standards for engineering materials data. The preliminary results of data communication between the two systems demonstrated the feasibility and efficiency of materials database interoperability, which constructs an interoperation framework that can be seamlessly integrated into the high-throughput First Principles material databases and thus advance the discovery of novel materials in fuel cell applications.