Analysis of the open-hole compressive strength of spruce

Open-hole compression tests on Sitka spruce ( Picea sitchensis Carr.) were conducted, and the effect of the hole notch on the compressive strength has been investigated. A circular hole was cut at the centre of the longitudinal (R)-radial (R) plane. A compression load was applied to the specimen along the L or R direction, and the nominal stress at the onset of nonlinearity and the nominal compressive strength were obtained. In the test, the diameter of the hole was varied, and the effect of the diameter was analysed based on point stress criterion (PSC). It was revealed that the notch sensitivity of Sitka spruce was not so significant, and this tendency was more pronounced for the compressive strength in the R direction than in the L direction. Despite the notch insensitivity, however, the open-hole compressive strength could be predicted appropriately by the PSC.