St. Venant's theorem

St. Venant's theorem states that among all objects with the same cross-sectional shape and area, a long, uniform bar will experience the smallest total deformation (such as bending or twisting) when subjected to external forces. Essentially, it tells engineers that the most efficient, least-absorbing shape for resisting certain stresses is a straightforward, uniform cross-section. This theorem helps in designing structures to ensure they are strong and stable, by allowing predictable and minimized deformation under load.