Fatigue Strength of Welded Joints in Very High Cycle Fatigue Region

• Project/Area Number: 24656277
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Single-year Grants
• Research Field: Structural engineering/Earthquake engineering/Maintenance management engineering
• Research Institution: Nagoya University
• Principal Investigator: HANJI Takeshi 名古屋大学, 工学(系)研究科(研究院), 准教授 (80452209)
• Project Period (FY): 2012-04-01 – 2014-03-31
• Project Status: Completed (Fiscal Year 2013)
• Budget Amount: ¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000); Fiscal Year 2013: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2012: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000)
• Keywords: 超高サイクル疲労 / 溶接継手 / 鋼橋

Research Abstract

In this study, focusing on the very high cycle fatigue region where fatigue life is more than ten million cycles, fatigue strength of welded joints was investigated.
Very high cycle fatigue tests were performed by using a bending fatigue testing machine, which can apply cyclic loads with high frequency to specimens due to the rotation of an eccentric mass in a motor. The test results revealed that the lowest stress range when the specimen failed was about 60N/mm2, which is almost equivalent to the fatigue limit proposed in the high cycle fatigue region.