Smart material

About: Smart material is a research topic. Over the lifetime, 3704 publications have been published within this topic receiving 74280 citations. The topic is also known as: intelligent material & responsive material.

Effects of adhesive on the electromechanical response of a piezoceramic-transducer-coupled smart system

Abstract: The electro-mechanical (EM) impedance method is gradually emerging as a widely accepted technique for structural health monitoring and systems identification. The method utilizes smart piezoceramic (PZT) transducers intimately bonded to the surface of a structural substrate. Through the unique electro-mechanical properties of the PZT transducers, the presence of damage, as well as the dynamical properties of the host structure are captured and reflected in the electrical admittance response. In the present work, the effect of the bond layer on the electro-mechanical response of a smart system is being studied. Experiments with the EM impedance method were performed on laboratory-sized beams. Consequently, the effects of shear lag due to the finite thickness bond layer were successfully identified. This was followed by the theoretical analysis of shear lag effects. It was found that the induced strain behavior of the structural specimen in question is inevitably modified by the presence of shear lag between the PZT transducer and the structural substrate. Subsequently, the EM admittance response of the beam specimens were simulated based on the results gathered from the theoretical analysis. Incidentally, it was found that the theoretical model clearly depicts the trends of the measured response.

Multifunctional polymer composites

Abstract: This paper reviews research within the Structural Materials Centre, DRA Farnborough into adding additional functionality to polymer composite materials in order to increase their usefulness in addition to the traditional role of structural materials. Demand for greater value for money and cost effectiveness has driven materials scientists and engineers to look at ways of adding value to these materials by getting them to perform functions other that those originally envisaged, that is carrying load, being rigid and not buckling. This might simply be by combining materials together as hybrids to save weight or cost or perhaps to improve toughness without compromising the original properties. Alternatively, totally unrelated performance might be sought, such as the ability to sense and locate damage, these materials having been termed smart materials. In this paper the behaviour of a number of polymer composite multifunctional materials is presented, with examples drawn mainly from work in the Structural Materials Centre at DRA Farnborough. The review covers smart materials and structures, materials designed to absorb electromagnetic radiation and materials optimised for energy absorption.

A Novel Concept for Strain Sensing Based on the Ferromagnetic Shape Memory Alloy NiMnGa

Abstract: This paper reports on a novel approach of using magnetic shape memory (MSM) alloys as smart materials in mechanical sensing. The presented concept enables the measurement of tensile strain. The underlying sensor mechanism is based on the reorientation of the martensite variants of the tetragonal unit cell of the MSM alloy (MSMA) which can be induced by either a magnetic field or a mechanical stress. In the novel concept, a magnetic bias field exerts a restoring force opposing the externally applied mechanical stress. The magnetic stray field at the rim of an MSMA sample, measured using a conventional Hall sensor, is used as the sensor signal. The operating principle was experimentally verified using a custom-made tensile test setup. A linear dependence of the magnetic flux density of the stray field on the mechanical strain was observed.

Science of Advanced Materials

Abstract: In this article an overview of the developments, importance and applications of some advanced materials have been discussed. The materials which have been discussed are: nanomaterials, smart materials, self cleaning materials, superconductors, multifunctional materials, semiconductors, biological materials and environment friendly materials. It is emphasized that these materials have lot of impact on the society.

Innovative Materials for Aircraft Morphing

Abstract: Reported herein is an overview of the research being conducted within the Materials Division at NASA Langley Research Center on the development of smart material technologies for advanced airframe systems. The research is a part of the Aircraft Morphing Program which is a new six-year research program to develop smart components for self-adaptive airframe systems. The fundamental areas of materials research within the program are computational materials; advanced piezoelectric materials; advanced fiber optic sensing techniques; and fabrication of integrated composite structures. This paper presents a portion of the ongoing research in each of these areas of materials research.