Mixed Mode Crack Propagation in Concrete

摘要

Two smeared crack approaches to fracture of concrete in mixed mode areimplemented in two-dimensional nonlinear concrete elements: (1) tensile stress transfer across cracks and (2) tensile plus shear stress transfer across cracks. To corroborate the analytical model a notched beam under mixed mode loading is then analyzed. In both cases, the stiffnesses normal and parallel to the crack were modified to insure a positive definite stiffness matrix. Stresses were corrected and set as functions of the crack slip and crack opening. Equilibrium iterations were implemented to redistribute stress. In both cases, acceptable agreement was found between analytical predictions and experimental results. The consideration of shear stress transfer yielded better predictions, but requires consideration of a non-symmetrical stiffness matrix. (JES)