| Project/Area Number |
01460165
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
船舶構造・建造
|
|---|
| Research Institution | Hiroshima university |
|---|
Principal Investigator |
YAO Tetsuya Hiroshima Univ., Faculty of Eng., Professor, 工学部, 教授 (20029284)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
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
|
| Project Status |
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 |
|---|
| Research Abstract |
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.
|
