In composites, this is the material that provides strength in a composite?

• A. Reinforcement
• B. Matrix
• C. Refuse
• D. Reduce

Answer: (A)

In composites, the strength comes mainly from the reinforcement. This phase, usually fibers such as glass, carbon, or aramid, carries most of the applied load and provides high tensile strength and stiffness along its length. The matrix surrounding the reinforcement binds the fibers together, distributes stresses between them, and protects them from environmental damage, but the primary strength is from the reinforcement. For example, carbon fiber in a carbon fiber–reinforced polymer carries the load, while the epoxy matrix keeps the fibers in place and helps transfer the force between them. The other options aren’t materials that provide the main strength, and one of them isn’t a material at all.