Study on Load Carrying Capacity of Offshore Structure with Damaged Member
Grant-in-Aid for General Scientific Research (B)
|Allocation Type||Single-year Grants|
|Research Institution||Hiroshima university|
YAO Tetsuya Hiroshima Univ., Faculty of Eng., Professor, 工学部, 教授 (20029284)
MIYAGAWA Yoshio Hiroshima Univ., Faculty of Eng., Research Associate, 工学部, 助手 (50229803)
FUJIKUBO Masahiko Hiroshima Univ., Faculty of Eng., Assoc. Prof., 工学部, 助教授 (30156848)
MICHIMOTO Jun-ichi Hiroshima Univ., Faculty of Eng. Presently Marine Safety Academy Assoc. Prof., 助教授 (80106806)
|Project Period (FY)
1989 – 1991
Completed(Fiscal Year 1991)
|Budget Amount *help
¥5,800,000 (Direct Cost : ¥5,800,000)
Fiscal Year 1991 : ¥1,600,000 (Direct Cost : ¥1,600,000)
Fiscal Year 1990 : ¥900,000 (Direct Cost : ¥900,000)
Fiscal Year 1989 : ¥3,300,000 (Direct Cost : ¥3,300,000)
|Keywords||Tubular Bracing Member / Buckling / Plastic Collapse / Denting Damage / Offshore Structure / Idealized Structural Unit Method / finite Element Method / Collapse Test / Elastoplastic Large Deflection Analysis / 局部座屈 / 円筒部材 / 理想化構造要素 / 曲げ損傷 / 凹損|
In this study, the influences of denting damage on strength and rigidity of tubular bracing members in offshore structures have been investigated both experimentally and theoretically. it has been found that :
1. A dented part is accompanied by residual stresses, and the bottom of a dent is almost yielded.
2. Both geometry of a dent and the residual strains and stresses affect the strength -and rigidity of a tubular bracing member.
3. When a dent is objected to compressive force, the ultimate strength is reduced by a dent. After the ultimate strength has been attained, the dent becomes to crow and local shell buclilinc, l takes place near the end of a dent bottom.
4. When a dent is subjected to tensile force, the rigidity decreases due to a dent. However, a dent is recovered with the increase of load, and the fully plastic strength is not so much affected by a dent.
5. Under a cyclic loading, a crack easily initiates at the end of the dent bottom.
The idealized structural unit for a dented tubular member under axial tension is developed improvinal the unit for a dented tubular member under axial compression. It has been found that further improvements are necessary as indicated below.
1. Growth of a dent under compressive force and recovery of a dent under tensile force should be considered.
2. The influence of a dent on rigidity should be considered especially when a dent is under tensile force.
3. The influence of residual stresses at a dented part should be considered.
Research Output (1results)