In structural engineering, what does 'stiffness' refer to?

Stiffness in structural engineering describes a material's ability to resist deformation under applied load. This property is crucial because it determines how much a structure will deflect or change shape when forces are applied. High stiffness means that a structure will deform very little in response to loads, which is vital for maintaining the integrity and functionality of buildings, bridges, aircraft, and other constructions.

It is often quantified as the ratio of the applied force to the resulting displacement, emphasizing the relationship between stress and strain. In structural applications, materials or structural shapes with greater stiffness are often preferred because they provide better load-bearing capacity and durability, ensuring safety and performance throughout their expected lifespan.

This understanding of stiffness is critical in design and analysis, as it helps engineers predict how structures will behave under various loads and conditions, contributing to sound engineering practices.