Briefing: Design punching shear capacity of wood-based panels

Punching shear capacity is one of the mechanical properties needed in the traditional design calculation method for assessing the concentrated load capacity of wood-based panels. A method for calculating the punching shear capacity of oriented strand board from its planar shear strengths has recently been proposed. Specifically, it is for oriented strand board loaded by way of a 25-mm dia. disc. This paper presents tests of the applicability of the proposedmethod to medium-density fibreboard loaded using a 25-mm dia. disc and to oriented strand board loaded through a 50-mm dia. disc. Design punching shear capacity, based on the Eurocode 5 recommendation for the effect of load duration on panel load capacity, is assessed in the light of recent test results showing the effect of load duration on punching shear capacity. Calculated oriented strand board and medium-density fibreboard punching shear capacities from the proposed method fall within 12% of the respective measured capacities. A comparison of the load-duration test results and the Eurocode 5 load-duration provisions indicates that the latter is conservative for punching shear capacity assessment under long-term loading. Further testing and validation of this proposed method should lead to the realisation of its potential benefits in panel design.