The Influence of Sample Thickness on the DCDC Fracture Test

摘要

The double cleavage drilled compression (DCDC) fracture test uses axial compression to drive stable cracks in glasses and brittle polymers. The cracks are generated by regions of tension in a rectangular column of material containing a central hole. The observed relationship between crack length and the applied axial stress is fitted with a two-dimensional finite element model to estimate fracture toughness. The model is applied to previous DCDC experimental results for poly(methyl methacrylate) (PMMA) samples of varying thicknesses. Both plane stress and plane strain cases are considered. Three dimensional finite element models of the DCDC test indicate plane stress analysis is the most applicable condition and suggest explanations for the effect of sample thickness.