The project will deal with a prediction of the bearing capacity of a timber beam with respect to
crack initiation and growth that occurs due to presence of notches. To reach this goal both
numerical model is to be developed and the material strain energy release rates of a common
structural softwood – Norway spruce - in main modes will be determined using small scale
experiments. To verify the prediction power of the numerical model, two hundred experiments of
artificially notched beams of real scale will be tested under arbitrary loads. The project will result
in knowledge and method for assessment of timber beams with cracks under complex
loading. The key research questions of the project are: (i) is it possible to use strain energy
release rate obtained on small scale samples in real beams? (ii) how is the fracture phenomena
in timber beams influence by orientation of tree rings? Findings of the project are important for
both research dealing with theoretical models and following and more applied fields such as
civil engineering since both have missing gaps in this knowledge.