It is well known that barely visible damage is often induced in composite structures subjected to out-of plane impact, and the mechanical properties of the composites decrease markedly. In this study, some element technologies for the detection of the damage are explained. Those are (1) the technologies for the arrangement of embedded small-diameter optical fibers which have no serious effect on the mechanical properties of composites, (2) the technologies for the egress of the optical fibers using “the embedded connector for smart structures” which can be trimmed without care about the optical fibers, (3) the technologies for the damage detection system that has the functions for data acquisition and analysis, the evaluation of the initiation and the position of damage, and the visualization of damage information. The impact test using the composite airframe demonstrator is conducted. The sensors embedded in the upper panel of the stiffened cylindrical composite structure with 1.5 m in diameter and 3 m in length, are FBG sensors for strain measurement and the optical fibers for optical loss measurement. The detection of damage in the composite structures using a developed damage detection system is demonstrated.

Date Published: 14 August 2003
PDF: 8 pages
Proc. SPIE 5054, Smart Structures and Materials 2003: Industrial and Commercial Applications of Smart Structures Technologies, (14 August 2003); doi: 10.1117/12.483874

Published in SPIE Proceedings Vol. 5054:
Smart Structures and Materials 2003: Industrial and Commercial Applications of Smart Structures Technologies
Eric H. Anderson, Editor(s)