Influence of Friction Inhibition on Lateral Resistance of Timber Joints

Abstract

Although researches on lateral resistance of timber joints have shown that joint movements are sometimes inhibited by friction generated between members, the effects of this resistance have not been clearly elucidated. Therefore, in this study, the influence of friction inhibition on the test results was analyzed. Bolted, nailed, and screwed joints were tested. Two methods of friction inhibition were applied: loosely tightening of fasteners, and inserting Teflon sheet and grease between members. It becomes clear that a static frictional appearing at the beginning of testing was sufficiently inhibited using the methods. In the case of loosely tightening, although the friction was sufficiently inhibited at the beginning of test, frictional resistance was gradually increased as the displacement of joint is increased. An effect of friction inhibition was clearly appeared in the mechanical characteristics. In particular, initial stiffness was strongly influenced as it decreased by 27-48%.