In laminated composites, what term describes the separation that can occur under overload?

In laminated composites, what term describes the separation that can occur under overload?

• A. Crack propagation
• B. Disbonds
• C. Delaminations
• D. Fracture

Answer: (B)

This question focuses on interfacial failure modes in laminated composites—how layers separate at their bonding interfaces when overloaded. The separation between adjacent plies at the bond line is called a disbond. It happens when the adhesive or the bond between layers fails, causing the laminae to pull apart rather than the material inside a ply cracking or breaking. This is different from crack propagation, which is the growth of a crack within a ply, and from fracture, which is the actual breaking of material. Delamination also refers to layer separation but is often described in the context of cracks propagating along the ply interfaces; the term disbond emphasizes the loss of adhesion at the interface itself due to overload, which is why it’s the best fit here.

This question focuses on interfacial failure modes in laminated composites—how layers separate at their bonding interfaces when overloaded. The separation between adjacent plies at the bond line is called a disbond. It happens when the adhesive or the bond between layers fails, causing the laminae to pull apart rather than the material inside a ply cracking or breaking.

This is different from crack propagation, which is the growth of a crack within a ply, and from fracture, which is the actual breaking of material. Delamination also refers to layer separation but is often described in the context of cracks propagating along the ply interfaces; the term disbond emphasizes the loss of adhesion at the interface itself due to overload, which is why it’s the best fit here.