Fracture analysis in the modified split-cantilever beam using the classical theories of strength of materials

The modified split-cantilever beam is a specimen type applied in fracture mechanics to measure the mode-III fracture properties of composites. In this paper an improved beam model is developed, which is based on the superposition of four different effects. The analytical model is validated by numerical calculations using the finite element software ANSYS and it is demonstrated that the agreement is very good between the analytical and the numerical models. Experimental measurements are also performed on unidirectional glass/polyester composite specimens, and a very good agreement is obtained between the results of the analytical model and the experiments. Apart from the excellent accuracy of the beam model it is shown that the modified split-cantilever beam has an important role in fracture mechanics, because it applies the same specimen geometry as the standard mode-I and mode-II tests and it is suitable to investigate the mode-III fracture properties in a quite extended crack length range.