高接触庄における木材と鋼材の摩擦係数: 鉄骨木質構造の研究　その9

摘要

本論文は木材と鋼材の接触部に生じる摩擦について実験的に考究したものである。というのは，筆者が取り組んでいる木材の割裂問題の研究が摩擦を避けては前進困難な段階に立ち至ったからである。ボルトやドリフトピンによる木材接合部の割裂には，これら鋼製接合具からの接触圧とともに摩擦力が関与するであろうことは容易に想像できる。摩擦力は木材の円孔周辺の応力状態に影響を及ぼ%Reviewing the modern knowledge of Tribology and the past experimental data on friction, the coefficient of friction between wood and steel is not well known especially under a high contact pressure. Thus, a new testing method named compression-pullout test is introduced to measure the sliding coefficients of static and kinetic frictions between wood and steel plates under heavy loading. The most important finding is that the friction is categorized into complete and incomplete frictions. The former is the case that the relative displacement between wood and steel is identical to the sliding as a rigid body, while the latter is that plastic deformation due to shear yielding of wood is associated with the sliding. Heavy contact especially with rough steel is apt to bring incomplete friction, in that the coefficient of friction is smaller than that of the complete friction under light contact. This means that the Amontons-Coulomb's law is not valid in the entire range from light to heavy contact.