Grant-in-Aid for Scientific Research (A).
|Allocation Type||Single-year Grants |
|Research Institution||Osaka University (1999-2000)|
Hiroshima University (1998)
YAO Tetsuya Osaka University, Graduate School of Engineering ; Professor, 大学院・工学研究科, 教授 (20029284)
FUJIKUBO Masahiko Hiroshima University, Faculty of Engineering ; Professor, 工学部, 教授 (30156848)
KIM Yuchol Welding and Joining Research Institute ; Associate Professor, 接合科学研究所, 助教授 (20144529)
HAYASHI Shigehiro Graduate Scool of Engineering ; Associate Professor, 大学院・工学研究科, 助教授 (60263216)
YANAGIHARA Daisuke Hiroshima University, Faculty of Engineering ; Research Associate, 工学部, 助手 (10294539)
KITAMURA Mitsuru Hiroshima University, Faculty of Engineering ; Professor, 工学部, 教授 (40195293)
正岡 孝治 大阪府立大学, 工学部, 講師 (10244659)
|Project Period (FY)
1998 – 2000
Completed (Fiscal Year 2000)
|Budget Amount *help
¥15,900,000 (Direct Cost: ¥15,900,000)
Fiscal Year 2000: ¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 1999: ¥7,300,000 (Direct Cost: ¥7,300,000)
Fiscal Year 1998: ¥5,600,000 (Direct Cost: ¥5,600,000)
|Keywords||Ultimate Longitudinal Strength / Buckling Strength / Ultimate Strength / Progressive Collapse Analysis / Idealized Structural Unit Method (ISUM) / Smith's Methos / Continuous Stiffened Plate / Stiffener Tripping / 座屈・塑性崩壊 / 理想化構造要素法 / 有限要素法 / 船体桁 / 溶接残留応力 / 初期たわみ / 座屈・塑性崩壊強度 / 簡易計算法 / 逐次崩壊挙動|
1. Analytical formulation is derived to evaluate local buckling strength of continuous stiffened plate subjected to bi-axial thrust considering the interactions between panel and stiffener. Analytical formulation is also derived to evaluate the ultimate strength of continuous stiffened plate under thrust.
2. The influences of transverse thrust and lateral pressure on buckling strength and ultimate strength of continuous plate with and without stiffeners are clarified, and the formulas to evaluate buckling/ultimate strength are derived. These are implemented into the method of progressive collapse analysis based on the Smith's method.
3. In case of local panel accompanied by initial deflection of a hungry-horse mode, deflection and plastic deformation are localised at a certain part of the plate while elastic unloading takes place in the remaining part of the plate. A plate element of the Idealized Structural Unit Method (ISUM) is developed which can simulate such behavior accurately.
his ISUM element is combined with a thin-walled beam-column element which can simulate bi-axial flexural-torsional buckling behaviour, and is applied for the collapse analysis of a continuous stiffened plate subjected to bi-axial thrust. It is demonstrated that this element shall be effective for the collapse analysis of a hull girder under loingitudinal bending.
5. 1/10-th welded steel scale models of a Chip Carrier are fabricated and the collapse tests are conducted on these models under the sagging condition. It is found that the buckling collapse of the deck and the upper part of the side shell plating become the trigger of the overall collapse of the hull girder.
6. Benchmark calculation is performed on 180 stiffened plates with different combination of panel aspect ratio, panel thickness, type of stiffener and size of stiffeners. Two cases are considered with and without welding residual stress. 10 different methods are applied. It has been concluded that scatter takes place in the calculated results depending on the conditions and assumptions in the individual calculation methods.
7. Benchmark calculation is performed on 4 existing vessels and a 1/3-scale welded steel frigate model to evaluate ultimate longitudinal strength applying 8 different methods. It has been concluded that the calculation method which can simulate the actual collapse behavior accompanied by localisation of deflection and plastic deformation as well as tripping of stiffeners.
8. The Smith's method using accuately derived average stress-average strain relationships of stiffened plate element is recommended as the best method to evaluate ultimate longitudinal strength of a ship hull girder. Less