18 May 1999 Damage assessment in hybrid laminates using an array of embedded fiber optic sensors
Author Affiliations +
Hybrid laminates typically consist of alternate layers of fiber-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 mechanism 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 fiber bridging. To facilitate the development of a unified model for both crack and damage growth processes, a remote sensing system, reliant upon fiber optic sensor technology, has been utilized to monitor strain within the composite layer. The fiber 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 price 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.
© (1999) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Timothy S. P. Austin, Margaret M. Singh, Peter J. Gregson, John P. Dakin, Philip M. Powell, "Damage assessment in hybrid laminates using an array of embedded fiber optic sensors", Proc. SPIE 3671, Smart Structures and Materials 1999: Smart Systems for Bridges, Structures, and Highways, (18 May 1999); doi: 10.1117/12.348677; https://doi.org/10.1117/12.348677

Back to Top