Empirical Punching Shear Failure Theory for Oriented Strand Boards: Preliminary Study

In characterizing the mechanical properties of oriented strand boards (OSBs), the punching shear capacity is not normally determined. Any attempt at developing a failure theory for punching shear from the planar shear strengths and a hypothetical shear perimeter that is similar to the approach in concrete should be most welcome by OSB designers. Fortunately, the planar shear strengths of OSBs are gradually being documented. The planar shear strengths and the punching shear capacities under a 25-mm-diameter load applicator of six OSB panels with thicknesses ranging from 9 to 18 mm have enabled a preliminary assessment of the optimum position of the hypothetical shear perimeter in an empirical punching shear failure theory for OSB. It is shown that a hypothetical shear perimeter that is a distance equal to the thickness away from the boundary of the loaded area enables the prediction of punching shear capacities that are roughly 75% of the measured punching shear capacity for one panel and within 10% of the measured punching shear capacities for the other five panels. Given that punching shear capacity of OSBs is rarely documented, and subject to future validation by other OSB panels, this empirical failure theory could be potentially useful for estimating the punching shear capacity of oriented strand board.