Fatigue Strength and Crack Initiation-Propagation Behavior of Web-Gusset Welded Joints on I-shaped Girder under Variation of Principal Stress Direction

2016 Fiscal Year Final Research Report

• Project/Area Number: 26289147
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Structural engineering/Earthquake engineering/Maintenance management engineering
• Research Institution: Hosei University
• Principal Investigator: MORI Takeshi 法政大学, デザイン工学部, 教授 (10157860)
• Research Collaborator: MATUI Yoshiaki ; KIMURA Naoto ; HARADA Hideaki ; HIRANO Shuichi ; SATO Ayumu ; MURAKOSHI Jun
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 疲労強度 / 主応力方向 / 圧縮繰返し応力 / 移動荷重 / 面外ガセット

Outline of Final Research Achievements

Fixed point load fatigue tests (four points bending tests) and the moving load fatigue tests (wheel load driving tests) on I-section girder specimens with web-gusset welded joints have been per-formed in order to make clear the stress properties, fatigue crack initiation and propagation behavior from the weld toe of the joint, and the fatigue strength under variation in principal stress direction. The test results suggested that the positions along weld toe in which the largest major principal stress occurs gradually changes by the load position, the fatigue strength under moving loads is lower around 20 to 30% than the strength under the fixed point loads, fatigue crack extending along the weld toe is long compared with that in fixed point loads, and the fatigue crack after leaving from the weld toe propagates in more inclined direction compared with the direction perpendicular to the principal stress one.

Free Research Field

橋梁を中心とした鋼構造とその接合部の強度，補修・補強と維持管理