ボルト接合における応力伝達について : 集中荷重をうける木材の応力の直交異方性体としての弾性論的研究(その2)

抄録

The previous paper has analyzed how a concentrated force is transmitted into a orthotropic wood plate for the case shown in Fig. 3. This paper deals with those cases in which the stresses are transmitted from a bolt to a orthotropic wood plate. Since the diameter of a bolt-hole is usually made 1 mm bigger than that of a bolt itself, a external compressive force, for instance, is mainly transmitted to the region between the upper and lower bolts (Fig. 4 (a)). Hence in this case the stress distributions through wood are explained by the orthotropic model of elasticity depicted in Fig. 3 without taking any account of existence of the regions from the bolts to the free ends. By pouring some epoxy into a bolt joint, the bolt is expected to be free of excess play such that external forces can be transmitted through the whole region of wood. Actually it is recognized that epoxy-glued bolt joints improve satisfactorily in the sense of final strength as well as displacement (Fig. 2). For epoxy-glued bolt joints the stresses are provided by making some alternation to the original results which were proposed in the previous report. Validity of the theoretical solutions of stresses for both normal and epoxy-glued bolt joints is assured by comparing the experimental results.