MECHANICAL ANALYSIS OF LATERAL LOADING BEHAVIOUR ON JAPANESE TRADIOTINAL FRAME STRUCTURE DEPENDING ON THE VERTICAL LOAD

摘要

In this study, the evaluation of the influence of vertical force derived from roof weight on Kumimono bracket complex in Japanese traditional building was focused. The mechanical model was developed for a block put between beams, like single Kumimono, with being connected by short dowels and subjected to a constant vertical force. The block and beam were assumed as elasto-plastic body like wood. The behavior of block when horizontal force is applied is explained as follows: a constant stress caused by vertical load is distributed along the contact surface initially; as a horizontal force applied, the stress distribution is gradually inclined because of elastic deformation of block; a separation from beam occurs at an edge of the block when contact stress vanishes; the slope of stress distribution becomes larger as contact area decreases; plastic deformation progresses from the contact edge after compression stress exceeds its yield stress. The behavior of entire block can be predicted by considering the transmission of shear force by friction and wooden dowels together with the model.The lateral loading test for unit Kumimono specimen in the size of 2/3 scale was performed. The specimen was put on the sliding apparatus. The constant vertical force was applied through the cables so that its upper beam kept the horizontal. The relative slip and rotation of the block were measured. Different load levels were set as parameter; they were the expected level in the actual structures, its 2/3 and 1/3. The measured deformation behavior of the block agreed satisfactory with that of predicted by the model, which lead to the verification of the model.