Fracture in Structures
Pages 56

The dependence of the flexural load-deflection curve on both material fracture resistance and beam size is examined. The flexural strength/tensile strength ratio f^/ft, is proposed as a parameter which reflects material brittleness - a lower value for a more brittle material. Two flexural toughness indices are proposed which efficiently convey the general global shape of the load-deflection curve. Dependence of these structural indices on material fracture resistance is indirectly expressed by using parameters involving just the flexural and tensile strengths and the fiber length to reflect fracture resistance. The dependence of the ultimate shear strength of longitudinally reinforced beams on material fracture resistance is also expressed using only the flexural and tensile strengths. The semi-empirical formulae developed relating structural performance to ff and ft suggest a simple and efficient means of accounting for the influence of fracture resistance on structural behavior in the design code.