Effect of laser drilling on mechanical properties of fir (abies borisii regis) and spruce (picea excelsa) woodEffect of laser drilling on mechanical properties of fir (abies borisii regis) and spruce (picea excelsa) wood Δημοσίευση σε Συνέδριο Conference Publication 2015-11-082014enFir and spruce wood specimens, 20 × 20 mm in cross section and 340 mm long, were prepared with true radial and tangential surfaces. All lateral surfaces of the specimens were drilled by laser beams to a depth of 0.4 cm (1/5 of specimen thickness) with two drilling patterns (distance between holes 1 × 1 cm and 1 × 2 cm). After drilling, MOE and MOR in static bending, axial compression and toughness were determined and compared with non-drilled controls. MOE was not affected by the laser drilling but MOR was significantly increased. The increase in MOR was 12-13% for the drilled fir specimens as compared to controls and was significant only for the 1 × 2 cm pattern, while for spruce it was noted an even higher increase of 21-24% significant for both drilling patterns. Toughness strength of drilled fir and spruce specimens was lower than the non-drilled but the differences were not significant. Laser drilling had a positive significant impact in axial compression strength with an increase of 20-23% for fir and 19-27% for spruce, and no differences between the drilling patterns. The overall results imply that strength properties do not decline by the laser drilling and, thus, are encouraging for further evaluating the drilling effects on the liquid permeability of these refractory to impregnation species. http://creativecommons.org/licenses/by/4.0/The 5th RCCWS International Symposium Adamopoulos Stergios Passialis Constantinos Voulgaridis Elias Moustaizis Stavros Kortsalioudakis Nathanail Κορτσαλιουδακης Ναθαναηλ Petrakis Panagiotis Πετρακης Παναγιωτης Karastergiou Sotirios Foti Dafni Koutsianitis Dimitrios Voulgaridou Eleni Laser percussion drilling laser drilling laser percussion drilling