Structural energy dissipation in extreme loading events using shape memory alloys

Abstract

It is well known that composite materials have a poor resistance to the damage caused by the impact of foreign objects on their outer surface. There are various methods for improving the impact damage tolerance of composite materials, such as: fiber toughening, matrix toughening, interface toughening, throughthe- thickness reinforcements and selective interlayers and hybrids. Hybrid composites with improved impact resistance would be particularly useful in military and commercial civil applications. Hybridizing composites using shape memory alloys (SMAs) is one solution since SMA materials can absorb the energy of impact through superelastic deformation or recovery stress reducing the effects of the impact on the composite structure. The SMA material may be embedded in the hybrid composites (SMAHC) in many different forms and also the characteristics of the fiber reinforcements may vary, such as SMA wires in unidirectional laminates or SMA foils in unidirectional laminates only to cite two examples. Recently SMA fibers have been embedded in 2-D woven composites. As part of this PhD work, the existing theoretical models for woven composites have been extended to the case of woven SMAHC using a multiscale methodology in order to predict the mechanical properties and failure behavior of SMAHC plates. Also several parts of the model have been coded in MATLAB and validated against results extracted from the literature, showing good correlation.

Date of Award	1 Jun 2011
Original language	English
Awarding Institution	University of Bath
Sponsors	QinetiQ Ltd
Supervisor	Michele Meo (Supervisor)