Font Size: 

A new energy-based theory, Quantized Fracture Mechanics (QFM), is presented that modifies continuum-based fracture mechanics. The differentials in Griffith’s criterion are substituted with finite differences; the implications are remarkable. Fracture of tiny systems with a given geometry and type of loading occurs at quantized stresses that are well predicted by QFM. QFM is self-consistent, agreeing to first-order with linear elastic fracture mechanics (LEFM), and to second-order with non-linear fracture mechanics (NLFM): the equation of the R-curve is consequently derived. For vanishing crack length QFM predicts a finite ideal strength in agreement with Orowan’s prediction. The different fracture Modes (opening I, sliding II and tearing III), and the stability of the fracture propagations, are treated in a simple way. In contrast to LEFM, QFM has no restrictions on treating defect size and shape. As an example, strengths predicted by QFM are compared with experimental and numerical results on carbon nanotubes containing defects of different size and shape.