Analysis of fracture toughness of modified timber

This paper presents results of fracture toughness tests on DCB specimens made of natural and modified pine wood. The energy release coefficients G_a were calculated for both the materials under TL and RL crack propagation modes and the 1^st mode of loading. Relations between the energy release coeffcients G_aI and the stress intensity factors K_aI have been determined. The obtained test results are presented in the form of tables and diagrams.