Experimental and Numerical Estimation of Notch Bearing Capacity in Structural Timber Beams at General Location Using LEFM

Registration number: GA21-29389S
Provider: Czech Science Foundation
Solver: Ing. Jan Pošta, Ph.D.
Start: 01.01. 2021
End: 31.12. 2023
Partners: Institute of Theoretical and Applied Mechanics of the Academy of Sciences of the Czech Republic, vv i, Mendel University in Brno / Faculty of Forestry and Wood

The project aims to test and quantify the ability to predict the initiation of crack propagation from a notch in a structural timber beam, at any point on the beam. In order to estimate the bearing capacity at a given point, a numerical model will be created, which is capable of using FEM and LEFM to determine the energy balance when releasing the continuity of the model at a given point - node. This value will be compared with the value obtained for a given complex fracture mode using small-scale material tests of fracture properties on a reference and common structural wood in Europe, i.e. spruce. To compare the reliability of prediction based on material properties measured on small samples, 200 experiments will be performed on large-sized notched beams to answer these basic research questions, namely:

  • Is it possible to use the strain energy release rate in a given fracture mode to predict the same on large beams of the dimensions found in practice?
  • How big is the effect of changing the orientation of the tree rings on the fracture characteristics of wood?