A Study on the Method to Estimate Ship Hull Girder Ultimate Strength Considering Biaxial Compression in Bottom Stiffened Plates
A Study on the Method to Estimate Ship Hull Girder Ultimate Strength Considering Biaxial Compression in Bottom Stiffened Plates
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考虑底部加筋板双向受压的船体梁极限强度估算方法研究
DOI：
10.1115/omae2017-61430
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Tetsuo Okada
中科院分区：
文献类型：
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作者：
Yoshiaki Naruse;Yasumi Kawamura;Tetsuo Okada
本文研究了考虑双轴压缩的船体底加筋板的极限强度问题。首先，利用商用有限元软件LS-DYNA对双向受压加筋板进行了弹塑性有限元分析。通过对加筋板的破坏行为的观察，发现双向受压加筋板的有效宽度比一般结构规范(CSR)中的公式减小得更快。这是因为当横向压缩载荷较大时，会发生单半波模式的屈曲，而当只施加纵向压缩载荷时，往往会发生纵向多个半波模式的屈曲。在此基础上，提出了一个新的考虑双向压缩的加筋板极限强度计算公式，其中引入了三个新的参数来表示有效宽度的减小。其次，在CSR提供的传统Smith方法的基础上，通过引入上述加筋板极限强度的新公式，并对Smith方法中硬角单元的常规公式进行改进，提出了一种考虑船底双向压缩的船体梁极限强度估算方法。最后，将该方法估算的集装箱船双轴压缩船体横梁强度与有限元分析结果进行了比较，验证了该方法的有效性。
In this study, ship hull girder ultimate strength considering biaxial compression in bottom stiffened plates is investigated. Firstly, elasto-plastic finite element analysis is carried out for the stiffened plates under biaxial compression by using the commercial FEM software, LS-DYNA. From the observation of collapse behavior of the stiffened plates, it is found that the decrease of the effective width of the stiffened plate under biaxial compression is more rapid compared with the formula in the Common Structure Rules (CSR). This is because the buckling in one half-wave mode occurs when the transverse compressive load becomes larger, while the buckling with multi half-waves mode usually occurs in longitudinal direction when only longitudinal compressive load is applied. Based on the observation, a new formula to estimate ultimate strength of stiffened plates considering biaxial compression is proposed in which three new parameters are introduced which can represent the decrease of the effective width. Next, a method to estimate ultimate strength of hull girder considering the biaxial compression of ship bottom is developed based on the conventional Smith method provided in the CSR, by introducing the above new formula to estimate the ultimate strength of stiffened plates, and by improving the conventional formula of the hard corner element in the Smith method. Finally, the hull girder strength of a container ship under biaxial compression estimated by the proposed method is compared with the result of FEM analysis to show validity of the method.