Which mechanical property of steel is most critical when assessing a tower's resistance to buckling under compressive loads?

The mechanical property of steel most critical when assessing a tower's resistance to buckling under compressive loads is the modulus of elasticity, often denoted as 'E'. Buckling is a form of structural instability where a member under compression suddenly deflects laterally. The modulus of elasticity represents the steel's stiffness or resistance to deformation under stress. A higher modulus of elasticity indicates that the steel is more resistant to bending and deformation, making it less prone to buckling. While yield strength and tensile strength are important for assessing a material's resistance to permanent deformation or fracture, the modulus of elasticity directly governs its elastic stability and resistance to buckling. In structural design, the critical buckling load is inversely proportional to the square of the member's effective length and directly proportional to the modulus of elasticity and the moment of inertia (a geometric property related to the member's cross-sectional shape). Therefore, a steel with a higher modulus of elasticity will exhibit a greater resistance to buckling under the same compressive load and geometric conditions.