FOR THE DETERMINATION OF THE SPECIFIC FRA CTURE ENERGY G(F) OF WOOD

The procedure to determine the fracture energy for tension perpendicul ar to the grain of wood currently published in draft standards of CIB or nordtest is reported in its essential issues and subject to a criti cal review. In order to yield comparable results even for very differe nt specimens sizes two additional conditions for applicability are int roduced. In addition the equation for the determination of G(F) is ext ended to more complex loading situations. Own experimental investigati ons show the important effect of the shape of the notch tip on testing stability and on the scatter of the measured fracture energy rates. T herefore in contrast to the mentioned draft standards it will be propo sed to use consistently only specimens with a sharp notch tip.