stiffened

Stiffened is the past participle of stiffen, and it can function as an adjective or verb to describe something made rigid or more rigid. It is used across disciplines to indicate that a material, structure, or textile has been treated or reinforced to resist deformation.

In engineering, stiffening refers to the addition of stiffeners such as ribs, stringers, or corbels to a plate or shell. The stiffeners increase the panel's stiffness and critical buckling load, helping distribute stresses and prevent bending or buckling under compression. Common applications include aircraft fuselage and wing panels, ship hulls, and bridge structures, where stiffeners are riveted, welded, or bolted to the base member.

In textiles and fashion, stiffened fabrics are treated with resins, starches, gels, or pastes to hold a crisp shape. This technique is used for hats, collars, pleats, and corsetry, and in crafts like millinery and bookbinding. Stiffening can alter drape and hand, and care requirements vary depending on the chemical or method used.

In other contexts, stiffness can be introduced by design choices or materials, such as stiffened panels in furniture or signage. The term emphasizes the result—reduced deformability—without specifying the exact method used.