Size and strain rate effects in steel structures

The paper contains experimental and theoretical evidence on the joint influence of size and strain rate on the mechanical properties of steel. Applying basic principles of continuum mechanics and dimensional analysis, the conditions for the existence of a characteristic dimension and a characteristic strain rate of the material are derived. The form of the relations between homologous material properties is also established. Experimental results on 130 samples machined from a large steel plate and subjected to uniaxial tension up to rupture were processed in view of the criteria previously discussed. Regression equations for various material properties, such as the tensile strength, that consider coupling between size and strain rate, are finally presented.