Paper Title
Constraint Correction in Prediction of Refrence Temperature(t0)from Three Point Bending Specimen of Different Thickness by Weibull Stress (for RPV Material, 20mnmoni55 Steel)

Refrence temperature (T0) of 20MnMoNi55steel is calculated, in accordance with ASTM E-1921 for different thickness of Three Point Bending Specimen.Difference in thickness causes variation in constraint label which deviates from Small Scale Yielding (SSY) condition causing a non-conservative prediction of T0.In this study Finite Element Analysis is used to calculate Weibull Stress verses J-Integral plot with increase in loading label, for each thickness of the specimen and its respective SSY model.Experimental KJC value,for different thickness is corrected with its equivalent SSY model from the Weibull Stress verses J-Integral plot.The Corrected T0 values reflects too much over prediction of Refrence temperature T0 from E-1921due to deviation of SSY condition. Keywords - Weibull Stress,Small Scale Yielding, Reference Temperature(T0),Fracture Toughness,Constraint.