Mechanism of nailed joints with decayed wood under lateral force

Research Project

Project/Area Number	26850107
Research Category	Grant-in-Aid for Young Scientists (B)
Allocation Type	Multi-year Fund
Research Field	Wood science
Research Institution	Hokkaido University
Principal Investigator	Sawata Kei 北海道大学, 農学研究院, 講師 (10433145)
Research Collaborator	Sasaki Yoshihisa 北海道大学, 大学院農学研究院, 技術職員 Saito Nozomi 北海道大学, 大学院農学院, 大学院生 Takanashi Ryuya 北海道立総合研究機構, 林産試験場, 研究職員
Project Period (FY)	2014-04-01 – 2017-03-31
Project Status	Completed (Fiscal Year 2016)
Budget Amount *help	¥3,770,000 (Direct Cost: ¥2,900,000、Indirect Cost: ¥870,000) Fiscal Year 2016: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000) Fiscal Year 2015: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000) Fiscal Year 2014: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Keywords	釘接合 / 荷重変位曲線 / 腐朽範囲 / 接合寸法 / 多数本釘打ち / 錆 / 初期剛性 / 終局荷重 / 単位釘接合 / 荷重－変位曲線 / 終局耐力 / せん断性能 / 腐朽 / 釘腐食 / 繰り返し加力 / 材厚 / 加力方向 / 釘引抜き性能 / めり込み性能 / 腐食 / 質量減少率 / 釘径変化率
Outline of Final Research Achievements	This study conducted on the nail withdrawal tests, bearing tests of wood, tests of joints connected with a nail under lateral force, and tests of multiple nailed joints. The nail withdrawal strength could be estimated by using corrosion of nail and decay degree of wood. The decay affected the bearing strength rather than the nail withdrawal strength. The ultimate load of the nailed joints decreased as the sum of the sound regions distance in the main and side members was decreased. The initial stiffness significantly decreased when the main or side member had a decayed region in the boundary between the main and side members. The decrease of ultimate load of multiple nailed joints was noticeable rather than that of initial stiffness. This study could obtain the mechanism of nailed joints under lateral force corresponding to the degree of decay and the displacement level of nailed joints.