AE2009 Aerospace Materials
Use of Smart Materials in Aerospace Industry
List of Contents
2. Types and Applications of Smart Materials
1. Piezoelectric Material5
2. Shape Memory Alloys14
3. Magnetostrictive Materials20
4. Rheological Fluids22
This report will cover the different types of smart materials, and their applications in the aerospace industry. An introduction is made with regards to the background and history of smart materials, after which 4 different types of smart materials are introduced. Within each subsection, we will draw a relationship between the properties of the smart material and its molecular mechanism. This is followed by presenting an outline of their recent and future applications, and the experimental procedures and results done in recent researches to show the feasibility of these applications. In the Discussion section, we will be delving into the cost-effectiveness and feasibility of using smart materials in aerospace components. Finally, the conclusion will give an insight into the relationship between the use of smart materials and the design of future aircrafts.
Smart materials are defined as materials that can significantly change their intrinsic properties (mechanical, thermal, optical or electromagnetic), in a predictable and controlled manner in response to their environmental stimulus. In general, these materials can be categorized into 3 categories, namely thermal-to-mechanical (shape memory alloys), electrical-to-mechanical (piezoelectric), and magnetic-to-mechanical (magnetostrictive).
Materials engineering has undergone a major transformation in the recent decade, as atoms and molecules are no longer viewed and worked upon on the microscopic level, but now on the nanometer level. Materials requirements are becoming more complex, especially in the aerospace industry in which safety and cost-effectiveness often conflict against each other. It is no longer acceptable for materials to have a single function; they need to be multifunctional to save costs and weight. Smart materials are now replacing monolithic ones to achieve multiple functions at all scale levels. Hence, smart materials are essentially integrated into the use of aerospace components.
What differentiates smart materials from normal monolithic ones? Smart materials exhibit characteristics which most scientists would term as ‘intelligence’. This includes immediacy (the ability to respond in real time); transiency (the ability to respond to more than one environmental states); self-actuation (inherent intelligence within material); selectivity (having a discrete and predictable response); and lastly, directness (response is local to the ‘activating’ event).
The performance characteristics of aircrafts are often limited by properties of materials used in both the airframe and propulsion systems. With the recent advancement of materials technology, high performance materials are created, resulting in a breakthrough in the performance and efficiency of modern aircrafts. The discovery of smart materials provides cost-effective and innovative solutions to the limitations currently faced in the design of aircrafts. These smart materials perform specialized functions when exposed to external stimuli, and they are increasingly being used to replace conventional aircraft parts for better performance. In this report, we shall look at the current and future use of these smart materials in the aerospace industry.
The purpose of this report is to introduce the different types of smart materials and their applications in the aerospace industry. Recent and emerging uses of these smart materials will also be presented, with brief experimental...