Dependence of Peak Stress on Crack Inclination and Friction Coefficient During Compressive Fracture
In the present work, an experimental study to analyze the role of friction between the crack faces and crack inclination in compressive fracture of wood has been conducted. Different orientations of (parallel to grain) central slit cracks in wood samples were put under quasi-static uniaxial compression to measure the peak stress carried by the sample. In order to extend the analysis to different friction coefficients at the crack faces without altering other properties, the wood was kept unchanged while the crack faces were coated with paint and polish. The peak stress was largeley observed to increase with an increase in the crack inclination (wrt horizontal) and decrease in the friction coefficient between the crack faces.