Health Monitoring of Composite Structures Using Static and Dynamic End Effects

Michael Gecht
Work towards M.Sc. degree under the supervision of Dr. B. Karp and Prof. D. Durban
Faculty of Aerospace Engineering
Technion – Israel Institute of Technology

Structural components made of composites carry potential benefits for the main structure in improving its performance. However, their implementation in airborne platforms is relatively limited, mainly due to the nature of their failure modes and high sensitivity to stress concentrations. Another problem has its origin in the well-known difficulty to estimate stress fields within a composite structural component due to the reduced validity of Saint-Venant’s principle. A promising direction to optimal design with structural composites, promoted during recent years, is by employing structural health monitoring technologies. In particular, early detection of edge damage, typical of composites used for helicopter blades and critical for appropriate functioning. We present a study aiming to verify experimentally the ability of detecting small changes in end conditions, and possible cracking or delamination damage, by monitoring dynamic and quasi-static end effects in composite beam-like plates. Static and dynamic excitations were imposed to examine the ability of strain gauges, located near and far from the damaged area, to detect small variations in the beam end fixation condition. The emerging result is that measurements of static and dynamic end effects can serve as a reliable indicator for joint health state and for material damage detection. That finding can extend the scope of structural health monitoring systems to include damage at suspected locations and of critical joints, issues that currently prohibit further usage of structural component made of composites.

The talk will be given in Hebrew

Wed, 12-02-2014, 16:30 (Gathering at 16:00)

Classroom, ground floor, Library, Aerospace Eng.

Light refreshments will be served before the lecture

Health Monitoring of Composite Structures Using Static and Dynamic End Effects