Study on Load Carrying Capacity of Offshore Structure with Damaged Member
Grant-in-Aid for Scientific Research (B).
|Research Institution||Hiroshima university|
YAO Tetsuya Hiroshima Univ., Faculty of Eng., Professor, 工学部, 教授 (20029284)
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)
MIYAGAWA Yoshio Hiroshima Univ., Faculty of Eng., Research Associate, 工学部, 助手 (50229803)
|Project Fiscal Year
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 / 円筒ブレ-ス材 / 座屈・塑性崩壊 / デント損傷 / 海洋構造物 / 理想化構造要素法 / 有限要素法 / 耐荷力試験 / 弾塑性大たわみ解析 / 海洋構造物ブレ-ス材 / 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)