Which of the following is NOT a type of structural composite?

• A. Laminates
• B. Sandwich panels
• C. Laminates and Sandwich Panels
• D. Inorganic monolithic alloys

Answer: (D)

Structural composites come from combining two or more materials to gain properties that a single material alone wouldn’t provide. Laminates do this by stacking layers with different properties and bonding them together, giving higher strength and stiffness in useful directions. Sandwich panels also fit, using a lightweight core sandwiched between stiff skins to achieve very high bending stiffness for a given weight, something you can’t get from a single material.

Inorganic monolithic alloys, however, are not composites in that sense. They are a single material or a homogeneous alloy formed by mixing elements at the atomic level, not by combining distinct materials or geometries (like layers or a core–skin structure). So they don’t count as a type of structural composite.