Effects of Wood Decay on the Shear Performance of Nailed Timber Joint

Abstract

In this study, we used Fomitopsis palustris, a common brown rot fungus, to treat forced rot. A shear test was performed. After the test, the impact driving depth of the steel pin was measured. Test results, After reaching the maximum yield strength, deformation progressed while the load gradually decreased. Longitudinal Compression Test of Aged Sachalinensis (Abies Sachalinensis) and Aspect of Nailed Joining to Steel Plate Attachment It was suggested that the ultimate shear strength can be evaluated from the pin driving depth. showed a different trend. Also, at a decayed nail joint, the nail can be pulled out without breaking the nail head. As a result of comparing the decreasing tendency of the nail shear strength calculated based on the theory with the experimental results, it was found that the decayed nail joints The drop in nail shear strength at the early stage of decay is an exponential curve similar to that seen in the case of longitudinal compressive strength. said. European type yield using the bearing strength of wood estimated from the impact driving depth of steel pins *1 Degradation of shear resistance of nailed joints by wood decay was estimated experimentally. fungus (Fomitopsis palustris), which is commonly observed in Japan. After the decay treatment, we measured the compressive strength parallel to the grain and the single shear resistance of nailed joints, and the depth of steel pin penetration burst into the wood. Test results showed that degradation of the maximum shear resistance of the nailed joints at an early stage of decay was not as rapid as the degradation analogized by compressive strength, which is often fitted with an exponential curve. Tearing of nail heads, which caused brittle joint failures, was typically observed in the tests of sound nailed joints in this study. The nails of decayed joints, however, were pulled from the wood members before being torn off at their heads. This difference in failure mode resulted in a gradual decrease of lateral loads beyond the maximum resistance without sudden drops of loads. of steel pin penetrations, which showed the ultimate shear resistance of decayed nailed joints could be estimated from onsite measurement of the depth of steel pin penetration.