An end-notched beam test for specific fracture energy in mixed mode in timber

A simple method for achieving stable crack propagation in a beam notched at a support is presented. The method allows the measurement of fracture energy in mixed modeGf,mix. Results from a small number of laminated veneer lumber specimens suggest that there is a relationship betweenGf,mix and density and that the ratioGf,mix/(Gf,I+Gf,II) is about 0.35. Calculations of fracture energy in mode IGf,I and mode, IIGf,II did not coincide with values from mode-specific tests, indicating that an adjustment is necessary to take account of the interaction between the modes.