Which property best describes aramid fibers in composites?

• A. High stiffness and impact resistance
• B. Low stiffness with low toughness
• C. Very high density
• D. High toughness and impact resistance, with lower stiffness than carbon fibers

Answer: (D)

Aramid fibers in composites are valued for their ability to absorb energy and resist impacts, while offering moderate stiffness. This combination means they give high toughness and excellent impact resistance, yet their stiffness is lower than that of carbon fibers. In practice, aramids (like Kevlar) can tolerate significant deformation and prevent brittle failure, making them ideal for protective and impact-tolerant applications. So the description of high toughness and impact resistance, with lower stiffness than carbon fibers, best matches their behavior.