Fracture Energy Of Spruce Wood After Different Drying Procedures


  • Stefanie E. Stanzl-Tschegg
  • Elmar K. Tschegg
  • Alfred Teischinger


Wood drying, fracture energy, splitting force, orientation influence, felling time, micro-struclure


The effects of different wood drying procedures, of felling time (winter and summer), and of compass orientation within one tree (north and south side) on the fracture properties of spruce wood have been studied. A most useful parameter to characterize the fracture behavior, the specific fracture energy Gf, has been determined with a new splitting method. High-temperature (100-110 C) drying renders the lowest specific fracture energy (Gf) and fracture toughness (KIC) values in comparison with 20 C fresh air, 50-60 C (kiln)-drying and prefreezing (-20 C), and air-drying. Prefreezing to -20 C before air-drying provides similar values as 20 C and similar or slightly higher values as 50 C drying. Effects of felling time and of compass orientation could not be detected unambiguously.


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