Chapter 1 - The structural performance of ceramic matrix composites

• Published in: High Temperature Mechanical Behaviour of Ceramic Composites pp. 3 - 84
• Main Authors: Evans, A.G., Zok, F.W., Mackin, T.J.
• Format: Book Chapter
• Language: English
• Published: Butterworth-Heinemann 1995
• ISBN: 0750693991; 9780750693998
• DOI: 10.1016/B978-075069399-8/50002-5

This introductory chapter focuses on the behavior, performance, and experimental results of ceramic matrix composites (CMCs). The strong interest in continuous fiber-reinforced CMCs has arisen primarily because of their ability to retain good tensile strength in the presence of holes and notches. This characteristic is important because CMC components generally need to be attached to other components. This chapter is based on the recognition that mechanism-based models are needed, which allows efficient interpolation between well-conceived experimental matrix composites. The emphasis is on the creation of a framework that allows models to be inserted as they are developed and that can also be validated by carefully chosen experiments. Some of the basic thermomechanical characteristics of composites are first established with emphasis on interfaces and interface properties, as well as residual stresses in this chapter. Then, the fundamental response of unidirectional (1D) materials, subject to tensile loading, is addressed in the chapter, in accordance with several subtopics: mechanisms of nonlinear deformation and failure; constitutive laws that relate macroscopic performance to constituent properties; the use of stress-strain measurements to determine constituent properties in a consistent, straightforward manner; and the simulation of stress-strain curves. The discussion of 1D materials in the chapter is followed by the application of the same concepts to 2D materials, subject to combinations of tensile and shear loading. The objective of this chapter is to address the mechanisms of stress redistribution upon monotonic and cyclic loading as well as the mechanics needed to characterize the notch sensitivity.