Smeared cracking and discrete crack dilatancy applied to tension-shear model problems

In this paper, the performance of smeared crack and discrete crack dilatancy models applied to mixed mode fracture is evaluated.Fixed, rotating as well as hybrid rotating-to-fixed smeared crack models are considered.For each crack model format-specific input parameters such as the shear retention factor, the reduction of compressive strength due to lateral cracking, and the transition point from rotating to fixed are varied respectively.Elementary tension-shear model problems are considered including validation against recent mixed-mode lab tests.The results indicate that the fixed crack response is highly sensitive to the choice of shear retention factor, while the rotating crack results are sensitive to the adopted boundary conditions of the model problem.The hybrid crack formulation does not provide consistent advantages compared to the fixed or rotating crack formulations.The discrete crack dilatancy models are found to be more accurate in predicting the mixed mode response of the tests, although they tend to overestimate the shear strength.Reference is made to early work by Willam.