Localized buckling concerns the buckling of a beam's plate element; which term describes this phenomenon?

• A. Local Buckling
• B. Longitudinal
• C. Luminaire
• D. Maintenance

Answer: (A)

Local buckling happens when a thin plate element inside a beam’s cross-section—such as a web or flange between stiffeners—becomes unstable under compression and buckles in its own plane. This is a localized instability, confined to a small region of the plate, rather than the entire beam twisting or bending as a whole. That’s why the term describing this phenomenon is local buckling. It’s controlled by how slender the plate is (its width-to-thickness and boundary conditions) and by whether there’s enough stiffness or adequate stiffeners to restrain the plate. In design, you mitigate it by increasing plate thickness, adding stiffeners, or limiting the unsupported width-to-thickness ratio. The other terms don’t fit: they don’t name a plate-level instability, and they are unrelated concepts.