SHEAR-STRENGTH OF CANADIAN SOFTWOOD STRUCTURAL LUMBER

An experimental study has been conducted to evaluate the longitudinal shear strength of nominal 38 x 185 mm and 38 x 285 mm Canadian softwoo d select structural lumber using a two-span five-point bending test pr ocedure with test span to specimen depth ratios of 6 and 5. Based on A merican Society fur Testing and Materials shear block test results of small clear specimens, finite element analyses coupled with Weibull we akest link theory have been used to predict the shear failure loads of the lumber. Good agreement between the predicted and measured median failure loads has been observed. This study has shown that the Weibull shape parameter is species dependent, which yields a higher unit volu me shear strength under constant stresses; therefore, the characterist ic shear strength values adopted in the current Canadian Code on Engin eering Design in Wood might be conservative for select structural dime nsion lumber.