Ultimate Strength of Offshore Structures (Mainly Jack-up Rigs)

海上结构物的极限强度（主要是自升式钻井平台）

基本信息

批准号：
59460127
负责人：
UEDA Yukio
金额：
$ 4.1万
依托单位：
Osaka 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：
1984
资助国家：
日本
起止时间：
1984 至 1986
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-59460127/
关键词：
Offshore structure Jack-up rig Pipe structure Joint Dent Rigidity Ultimate strength 理想化構造要素法

项目摘要

Based on the Idealized Structural Unit Method, an ultimate strength analysis method was developed for the safety check of earthbound offshore structures. By this method the behaviors of the structures reaching ultimate strength under various loading conditions were investigated with consideration of the effects of local rigidity and strength.The object structure was divided into such elements as (1) joint, (2) pipe between two adjacent joints and (3) substructures composed of joints and pipes.T-joint consisting of cord and brace was assumed as the basic joint. Systematic theoretical and experimental studies were carried out on the rigidity and strength. As a result, simple estimating equations for the rigidity and ultimate strength were formulated.With this information, a new idealized structural unit, tubular joint element, consisting of springs, rigid bars and beam element was developed for T, Y and K joints in order to efficiently treat the local rigidity and strength in the whole structure analysis.Idealizing the elastic-plastic large deflection behavior of a pipe, an idealized pipe element was developed. Also, a similar element was developed for dented pipes.Using the above three idealized structural units, ultimate strength analyses were conducted for the whole structure of a jack-up rig and a jacket rig. Obtained were the following conclusions. (1) When the whole structure undergoes shear collapse due to horizontal load, ultimate strength is attained by yielding of the joints or buckling of the braces under compression depending on relative strength between the joints and braces. (2) The joint rigidity greatly influences the whole structural rigidity and ultimate strength. In addition, performing analyses of ultimate strength of a jack-up rig under survival and punch-through conditions, the safety of the structures in these cases was checked.

基于理想化的结构单位方法，开发了一种最终的强度分析方法，以对地球离岸结构进行安全检查。通过这种方法，通过考虑局部刚性和强度的影响，研究了在各种负载条件下达到最终强度的结构的行为。对象结构被分为（1）关节，（2）在两个相邻接头之间的管道和（3）由关节和管道组成的子结构之间。对刚性和强度进行了系统的理论和实验研究。结果，制定了对刚性和最终强度的简单估计方程式。与此信息一起，为T，Y和K关节开发了一个新的理想化结构单位，由弹簧，刚性条和梁元素组成的管状关节元素，以有效地处理整个结构中的局部刚性和强度分析中的固刚性。此外，开发了类似的元素，用于凹陷管道。使用上述三个理想的结构单元，对升空钻机和夹克钻机的整个结构进行了最终强度分析。获得以下结论。（1）当整个结构因水平载荷而发生剪切塌陷时，根据关节和支撑之间的相对强度，可以通过屈服或压缩牙套的接头或屈曲来实现最终强度。（2）关节刚性极大地影响了整个结构刚度和最终强度。此外，检查了在生存和打孔条件下进行升空钻机的最终强度的分析，在这些情况下，结构的安全性得到了检查。