权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Reseach on Strength of Ships and Offshore Structures Sbujected to Hydrostatic Pressure.

船舶及海洋结构物静水压强度研究。

基本信息

批准号：
61302049
负责人：
OHTSUBO Hideomi
金额：
$ 9.92万
依托单位：
University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Co-operative Research (A)
财政年份：
1986
资助国家：
日本
起止时间：
1986 至 1988
项目状态：
已结题

项目摘要

In order to obtain critical pressure to cause general instability of reinforced cylindrical shells, the buckling equations were derived based on the energy method. The buckling pressure is calculated and compared with the experimental ones indicating good accuracy of analytical model. Recent advances of numerically controlled machining ennable us to estimate buckling pressure of sttifend sylindrical shells accurately by experiments. Machined models can regarded as perfectly cylindrical shells, and the validity of modelling for numerical method will be abl to confirmed by comparing theoretical results with experiment. in order to analyse the ultimate strength of ship and offshore structures, idealized "plate element" and "stiffend element" in the framework of the idealized structural unit method (ISUM) were deceloped. A simple calculation method is developed to simulate the progressive collapse behavior of a cross section of a ship's hull under longitudinal bending moment. The dynamic pulse lateral bucling of a T-shaped section thin walled beam and the effectiveness of asymetric section steffners in large deflection due to static loads were studied by expriments with simplified calculations. A system is developed for probabilistic strength assessment of semi-submersibles under the extreme sea. Through numerical examples for a typical platform, the properties of critical section or dominant failure modes and their probabilities of occurrence are investigated. Crush analysis codes of structural members have been developed by using low-order finite elements, which have been applied to The analysis of the crushing behaviors of steel tubes as well as the collapsing behaviors of ring-stiffened circular cylinders subjected to external pressure. the validities of the developed codeshave been demonstrated through the comparisons of numerical results with the experimental observations.

为了得到加筋圆柱壳发生整体失稳的临界压力，基于能量法推导了屈曲方程。计算了屈曲压力，并与实验结果进行了比较，表明分析模型具有较好的精度。近年来数控加工技术的发展，使我们能够通过实验精确地估算加筋圆柱壳的屈曲压力。加工后的模型可视为理想圆柱壳，数值方法建模的有效性将通过理论计算结果与实验结果的比较得到证实。为了分析船舶和海洋结构物的极限强度，在理想结构单元法（ISUM）的框架内，发展了理想化的“板单元”和“加劲单元”。本文提出了一种简单的计算方法来模拟船舶船体横截面在纵向弯矩作用下的连续倒塌行为。通过试验和简化计算，研究了T形截面薄壁梁在静载作用下的动态脉冲侧向屈曲和非对称截面加劲肋的有效性。开发了一套半潜式平台在极端海况下的概率强度评估系统。通过一个典型平台的算例，研究了临界截面或主要失效模式的性质及其发生概率。本文采用低阶有限元法编制了构件的挤压分析程序，并将其应用于钢管的挤压性能和环肋圆柱在外压作用下的破坏性能的分析。数值计算结果与实验结果的比较表明了所开发程序的有效性。