ROTATIONAL FACTOR USING BENDING MOMENT APPROACH UNDER ELASTOPLASTIC SITUATION .1. NOTCH 3PB GEOMETRY

Theoretical determination of rotational factor is investigated in notc hed three point bend specimen considering the bending moment arising o ut of stress distribution in the plane of deformation and fracture. Th eoretical formulation and the determination of rotational factor is ba sed on the fact that resultant bending moment about a neutral axis mus t be zero. Since the stress distribution in the neighbourhood of the n otch tip is still a debatable issue, several possible combinations of ligament stress distributions are considered for both elastic and elas to-plastic situations. The rotational factor is found to be in the ran ge 0.26-0.32 for well below the general yield regime and around 0.43 f or the general yield situation. However, the experimental values of th e rotational factor are found to be in the range 0.50-0.56.