Influence of Thermal Softening of Wood on the Fundamental Performance of Drift Pin Joints I.

Influence on the bearing strength and stiffness of wood

Abstract

This study deals with the thermo-softening behavior of wood under the combined stresses in the drift pin joints of timber buildings. The purpose of this paper was to clarify the influence of thermal softening of wood on the bearing strength and stiffness, which was required to estimate the performance of the joints. The relations of bearing strength and stiffness to moisture content (MC) and temperature of wood samples were evaluated. The bearing test was conducted for the MC-conditioned sample by using the testing machine with the thermo-hygrostat. Both bearing strength and stiffness decreased with increasing MC and temperature, or with the promotion of the thermal softening. The decrease in both the strength and the stiffness in the longitudinal direction was larger than that in the transverse direction.