Introduction to Composite Materials

COURSE CONTENT  

The Nature of Composite Materials: Polymer Matrices: Ways of Classifying Polymers. Thermosets and Thermoplastic Polymers. Polymer morphology. Microstructure. Effect of Deformation on Polymer Morphology. Engineering Plastics. Composite materials. Structural Foam. Elastomers. Polymeric Mixtures. Liquid Polymeric Crystals. Typical Characteristics of Some Important Plastics. The Modern Technology of Plastics and Composite Materials – Possibilities and Prospects in the Greek Industry. Manufacturing technologies for polymers and composites.

Properties and Applications of Engineering Thermoplastics. Mechanics of Materials. Mechanical Behavior of Polymers: Stress-strain relations. Basic Equations and Theory of 2D Elasticity. Field equations. The 2D Elasticity Problem. Elastic and Viscoelastic Behavior. Creep in Polymers. Mathematical formulation of the creep problem. Reinforcing Fiber: Fiber Types. Continuous Fibers. Chopped fibers. Woven fabric reinforcements. Mat type reinforcements. Fiber Length Distribution. Fiber Orientation distribution. Voids. Lamina and Laminates. Fiber-Matrix Interface: Two Materials Adhesion. Elastic Behavior of Fiber reinforced Composite Materials: Elastic Properties of One Layer with Parallel Fibers. Elastic Properties of One Layer with Long Fibers and Random Orientation. Distribution of stress and strain along a single Fiber. Elastic Properties of Short Fiber Composite Materials. Definition of Damage in Composites. Interaction Between Cracks and Fiber. Fiber pull-out. Micro-mechanical models for the along the fiber and normal to the fiber direction. Shear Properties.

LEARNING OUTCOMES   

Understanding of the properties of composite materials as a basis for the improvement of the properties, manufacturing processes and design of products made from these materials. Although the emphasis is on the properties of the composite materials as a whole, a knowledge is required of the properties of the individual components: the fiber, the matrix and the interface between the fiber and the matrix. Students also understand the essence of composite materials technology which is, the ability to put strong stiff fibers in the right place, in the right orientation with the right volume fraction. Implicit in this approach is the concept that in making the composite material one is also making the final product. At first, the student learn about the classification and definition of composite materials as well as about the relation between composite materials and more traditional engineering materials and the manufacturing routes for products made from composite materials. Next, students proceeds to the properties of the fibers and matrices and their relation to microstructure and processing conditions. The concept of the fiber-matrix interface and the methods of measuring the bond strength are also presented to the students. Next, the geometrical aspects of composites with particular reference to the characterization of fiber volume fraction, fiber length distribution, fiber orientation in 2D and 3D, void content, etc. is presented to the students. Next to this, the students learn about the elastic properties of a UD lamina and comparisons between theoretical predictions and experimental results of different fiber-resin systems are given. Finally, the elastic properties of a laminate is studied and presented using classical lamination theory. Students also learn about short fiber composites, particulates as well as hybrid composites. A series of lectures is also devoted to the dynamic mechanical behavior of composites, thermal and mechanical fatigue, water absorption, fracture mechanics and crack propagation and a number of other of special topics which are updated each year.