Study on Load Carrying Capacity of Offshore Structure with Damaged Member

含损伤构件的海上结构承载能力研究

基本信息

批准号：
01460165
负责人：
YAO Tetsuya
金额：
$ 3.71万
依托单位：
Hiroshima university
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1989
资助国家：
日本
起止时间：
1989 至 1991
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-01460165/
关键词：
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

项目摘要

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.

在本研究中，从实验和理论上研究了凹痕损伤对海上结构中管状支撑构件的强度和刚度的影响。已发现：1．凹痕部位伴有残余应力，凹痕底部几乎屈服。2．凹痕的几何形状以及残余应变和应力都会影响管状支撑构件的强度和刚度。3．当凹痕受到压缩力时，最终强度会因凹痕而降低。达到极限强度后，凹痕变成乌鸦和局部贝壳buclilinc，l发生在凹痕底部末端附近。4．当凹痕受到拉力时，刚性会因凹痕而降低。然而，随着载荷的增加，凹痕会恢复，并且全塑性强度受凹痕影响不大。5．在循环荷载作用下，裂纹很容易在凹痕底部的端部萌生。在轴向受压凹形管构件的结构单元的基础上，改进了轴向拉凹形管构件的理想结构单元。已发现需要进一步改进，如下所示： 1．应考虑压痕在压缩力作用下的增长和在拉力作用下压痕的恢复。2．特别是当凹痕受到拉力作用时，应考虑凹痕对刚度的影响。 3．应考虑凹痕部分残余应力的影响。