Inelastic Response of a Deep Crack Single-Edge Notch Specimen Under Impact Loading

Abstract

Three-dimensional dynamic analyses are performed for a single-edge bend, SE(B), fracture specimen (a/W = 0.5) subjected to impact loading. Loading rates obtained in routine drop tower tests (terminal load-line velocity of 100 in./s or 2.54 m/s) are applied in the analyses. Explicit time integration coupled with an efficient element integration scheme is used to compute the dynamic response of the specimen. Strainrate sensitivity is introduced via a new, efficient implementation of the Bodner-Partom viscoplastic constitutive model. Material properties for A533B steel (a medium strength pressure vessel steel) are used in the analyses. Static analyses of the same SE(B) specimens provide baseline results from which inertial effects are assessed. Similarly, dynamic analyses using a strain-rate insensitive material provide a reference for the assessment of strain rate effects. Strains at key locations and the support reactions are extracted from the analyses to assess the accuracy of static formulas commonly used to estimate applied J values. In ertial effects on the applied J are quantified by examining the acceleration component of J . Results show that dynamic effects for the steel analyzed are negligible after twice a characteristic time that can be defined in terms of the first elastic period of the specimen.