Numerical Analysis of Mixed-Mode Cracking in Concrete Dams

Abstract

Since the establishment of the fictitious crack model (FCM) for crack analysis of the mode-I type in concrete by Hillerborg et al. [1], continuous research effort has been made to apply the concept to model mixed-mode fracture because most of the practical fracture problems in concrete are of the mixed-mode nature, involving mode-I and mode-II. This paper presents a numerical study of the mixed-mode fracture in concrete dams, using the extended FCM by Shi et al. [2]–[4]. For crack propagation, the frequently adopted maximum principal stress criterion is used, which is based on the notion that the mode-I condition is dominant at the tip of a mixed-mode crack. As the tip stress reaches the tensile strength of concrete a mixed-mode crack propagates. A main feature of this study is that normal and tangential tractions are applied directly to the crack surface, following specific tension-softening and shear-transfer laws.