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

A Study on Efficient Methods for Estimating Strength and Reliability and Their Application to Preliminary Structural Design of Large Floating Structures

强度和可靠性有效估算方法及其在大型浮动结构初步结构设计中的应用研究

基本信息

批准号：
15360469
负责人：
OKADA Hiroo
金额：
$ 6.4万
依托单位：
OSAKA PREFECTURE UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2004
项目状态：
已结题

项目摘要

1)Efficient methods are investigated for estimating strength and reliability of pontoon type VLFS under long crested waves from view point of preliminary design by analysis. Firstly, a simplified estimation method is presented for the probabilistic load effect of VLFS under irregular sea-state conditions. Next, a limit state and reliability analysis method is presented for the buckling and ultimate collapse strength of stiffened panels under combined compression, shear and lateral pressure in deck, bulkhead and bottom parts of VLFS. Then, the validity of the simplified estimation method is shown by using non-linear finite element analysis. The applicability of the methods is investigated through numerical examples for 5,000m-class VLFS under trial design for the severe sea state-condition in Tokyo Bay. Effects of design parameters such as plate thickness, stiffener and bulkhead space on characteristics of the reliability level are numerically shown by using sensitivity analysis.2)An ef … More ficient method is presented for estimating hydro-elastic behavior of VLFS modeled by a rectangular plate on the shallow water in oblique waves. Effects of incident wave-number, incident angle, aspect ratio and bending rigidity of the structure on the response behavior are investigated.3)Fatigue behavior of structural steels under multiple repeated loads as a part of basic studies on fatigue life estimation of marine structures. The fatigue behaviors such as the change of hysteresis loop energy and temperature rise rate of specimens under completely reversed tension and compression are investigated with much circumstance. A method for estimating the remaining fatigue life is presented by using a method combined the linear cumulative fatigue damage rule (Miner's rule) with above experimental results.4)The compressive ultimate strength of stiffened plates with corrosion is investigated by the non-linear finite element method. It is found that the ultimate strength is determined by the parameters of the most corroded cross section of stiffened plates. Simple design equation to estimate the ultimate strength is proposed by considering above results.5)Simplified method is presented for estimating the residual strength of corroded circular tubes under bending and compression. It is found that the above estimation results for effects of the reduced thickness due to corrosion on the ultimate strength deterioration are in comparatively good correspondence to analytical results based on elasto-plastic finite element method using shell elements. Less

1)本文从初步设计的角度出发，通过分析探讨了长峰波作用下浮箱式超大型浮体结构强度和可靠性的有效方法。首先，提出了一种不规则海况下超大型浮体概率荷载效应的简化估算方法。其次，提出了VLFS甲板、舱壁和底部加筋板在压缩、剪切和侧压力共同作用下的屈曲和极限破坏强度的极限状态和可靠性分析方法。然后，通过非线性有限元分析，证明了简化估计方法的有效性。通过东京湾5,000 m级超大型浮体试验设计的数值算例，研究了该方法的适用性。通过灵敏度分析，给出了板厚、加强筋和舱壁间距等设计参数对可靠度水平特性的影响规律 ...更多信息提出了一种计算斜波作用下浅水矩形板模型VLFS水弹性特性的有效方法。研究了入射波数、入射角、长宽比和结构弯曲刚度对响应行为的影响。3）作为海洋结构物疲劳寿命估算基础研究的一部分，研究了结构钢在多次重复载荷下的疲劳行为。研究了在完全反向拉压条件下，试样的滞回线能量和温升率的变化等疲劳行为。将线性累积疲劳损伤准则（Miner准则）与上述试验结果相结合，提出了一种估算剩余疲劳寿命的方法。4）采用非线性有限元方法研究了腐蚀加筋板的抗压极限强度。结果表明，加筋板的极限强度主要由腐蚀最严重截面的参数决定。综合考虑上述结果，提出了估算腐蚀圆管极限强度的简单设计公式。5）提出了计算腐蚀圆管弯曲和压缩剩余强度的简化方法。结果表明，上述腐蚀减薄厚度对极限强度劣化影响的估算结果与采用壳单元的弹塑性有限元分析结果具有较好的一致性。少