Four-point bending strength of key-hole side-edge-notched western hemlock (Tsuga heterophylla) wood

Abstract

Abstract The four-point bending strength of key-hole side-edge-notched (4KHSENB) western hemlock (Tsuga heterophylla Sarg.) has been determined with a focus on the effects of the notch length and hole size on the results. A hole notch with various lengths and hole diameters was cut at the mid-length in the longitudinal-radial plane. Bending loads were applied to the specimen along the depth direction at the two trisectional points of the span, and the nominal bending stress in general and at the onset of non-linearity was determined. The effects of the input parameters were analysed based on the elementary beam theory (EBT), the point stress criterion (PSC), and linear-elastic fracture mechanics (LEFM). It was found that the PSC and LEFM methods are effective for fitting the relationships between the side-edge-notched strength and notch length in the longitudinal and radial directions, respectively.