共查询到18条相似文献,搜索用时 62 毫秒
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简述了采用面元法计算船舶兴波阻力的原理,给出了Rankine源和Kelvin源两种格林函数的具体形式,并比较了两者的优缺点。最后以Wigley数学船型为例,总结出了一套完整的兴波阻力计算步骤。 相似文献
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本文基于格林函数的Rankine源函数对船舶运动中的兴波阻力展开计算,由此提升直接法的计算精度,保障船舶的航行安全。 相似文献
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一种计算非线性兴波阻力的基于NURBS的高阶面元法 总被引:1,自引:0,他引:1
文章开发了一种用于求解非线性兴波阻力问题的基于非均匀有理B样条(NURBS)的高阶面元法.该方法采用NURBS基函数表达物面几何和边界面上的源强分布.为了满足非线性自由面边界条件,开发了一个迭代算法;辐射条件通过采用网格错位的数值技术得到满足.以Wigley数学船型为例,在一系列的船速下计算了非线性兴波阻力.数值结果表明所提出的方法对于计算兴波阻力是精确和有效的. 相似文献
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将一种由典型的方尾流动物理模型(水流沿方尾下缘切向脱体)导出的数值方尾边界条件应用于高速多体船兴波问题计算。兴波波形与兴波阻力的数值计算采用基于非均匀有理B样条的广义高阶面元法,所得到的高速双体船算例与高速三体船算例的计算结果合理。 相似文献
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船体辐射运动是航行船舶波浪增阻的主要原因。文章基于频域势流理论推导出三维有航速船体辐射能量的具体表达式,其中流体运动速度势的计算采用了移动脉动源格林函数法,进一步根据获得的船体水动力系数和运动计算出航行船舶辐射运动引起的波阻增加,并与基于切片理论的现有方法进行了比较。对Wigley III、S175集装箱船及某型油船三类不同船型在不同航行工况下的波阻增加进行了详细的计算分析。研究表明三维辐射能量法相较于基于切片理论的方法具有更好的准确性和适用性,为船舶波阻增加的预报提供了快速有效的手段。 相似文献
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三体船在波浪中的运动响应是设计时重要的考虑因素之一。文章介绍了三体船运动计算的"三维移动脉动源法",以及计算结果和试验结果之间的对比,说明了该方法的精度。针对一型三体船设计,对不同的侧体布置方案进行了计算比较,初步分析了具有较好耐波性的布置方案。 相似文献
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结合厦门市环东海域综合整治建设项目丙洲区C标段吹填区软弱地基加固工程,对高真空强排水联合低能量强夯动力固结法加固吹填土软弱地基的施工技术进行了介绍,并经过标准贯入试验(SPT)、静力触探试验(CPT)以及荷载板试验(PLT)检测,其结果均满足设计的要求。同时,对加固效果进行的相关探讨,其部分结论为以后类似地基处理提供一定的参考。 相似文献
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ZHANGHai-bin RENHui-long DAIYang-shan GEFei 《船舶与海洋工程学报》2004,3(1):7-13
A wave load computation approach in direct strength analysis of semi-submersible platform structures was presented in this paper. Considering the differences in shape of pontoon, column and beam, the combination of accumulative chord length cubic parameter spline theory and analytic method was adopted for generating the wet surface mesh of platform. The hydrodynamic coefficients of platform were calculated by the three-dimensional potential flow theory of the linear hydrodynamic problem for platform with low forward speed. The equation of platform motions was established and solved in frequency domain, and the responses of wave-induced loads on the platform can be obtained. With the interpolation method being utilized, the pressure loads on shell elements for finite element analysis(FEA) were converted from those on the hydrodynamic computation mesh, which pave the basis for FEA with commercial software. A computer program based on this method has been developed ,and a calculation example of semi-submersible platform was illustrated. Analysis results show that this method is a satisfying approach of wave loads computation for this kind of platform. 相似文献
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集装箱船货舱区舱口角隅疲劳强度校核是集装箱船强度分析的重要内容之一,该文选择沪东中华造船(集团)有限公司即将建造的8 530 TEU集装箱船船中No.5货舱区Fr181处角隅作为疲劳强度分析对象.基于设计波法,选择全球航行海域波浪散布图进行波浪诱导载荷长期预报,获得四种典型的波浪载荷参数,然后在一个波浪循环内每隔30°取一相位,计算了其中三种最典型波浪载荷工况下上甲板角隅边缘和舱口围板角隅边缘的热点应力,确定最大应力范围及其位置,最后基于S-N曲线法进行疲劳强度校核. 相似文献
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针对规范公式不适用于小方形系数Cb0.6的船舶以及线性设计波法不能反映波浪载荷非线性特征的情况,使用非线性设计波法研究了一艘小方形系数船的波浪载荷长期预报极值和波浪载荷与波高非线性变化规律,给出了非线性设计波参数的选取办法。根据参数,用非线性设计波法计算了船舶的波浪附加弯矩,并与线性设计波和规范公式两种方法得到的波浪附加弯矩进行了比较分析。分析结果表明,非线性设计波法能够反映出波浪幅值较大时波浪载荷随波高非线性变化的规律,以及中拱、中垂状态下舯剖面波浪附加弯矩的非对称特征,较线性方法更为合理。 相似文献
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In a Thermal-Elastic-Plastic (TEP) FE analysis to investigate welding induced buckling of large thin plate welded structure such as ship panel, it will be extremely difficult to converge computation and obtain the results when the material and geometrical non-linear behaviors are both considered. In this study, an efficient FE computation which is an elastic FE analysis based on inherent deformation method, is proposed to predict welding induced buckling with employing large deformation theory, and an application in ship panel production is carried out. The proposed FE computation is implemented with two steps:(1) The typical weld joint (fillet weld) existing in considered ship panel structure is conducted with sequential welding using actual welding condition, and welding angular distortion after completely cooling down is measured. A TEP FE analysis with solid elements model is carried out to predict the welding angular distortion, which is validated by comparing with experimental results. Then, inherent deformations in this examined fillet welded joint are evaluated as a loading for the subsequent elastic FE analysis. Also, the simultaneous welding to assemble this fillet welded joint is numerically considered and its inherent deformations are evaluated.(2) To predict the welding induced buckling in the production of ship panel structure, a shell element model of considered ship panel is then employed for elastic FE analysis, in which inherent deformation evaluated beforehand is applied and large deformation is considered. The computed results obviously show welding induced buckling in the considered ship panel structure after welding. With its instability and difficulty for straightening, welding induced buckling prefers to be avoided whenever it is possible. 相似文献
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面元法预估导管螺旋桨水动力性能的一种新方法 总被引:2,自引:0,他引:2
采用一种新的方法预估导管螺旋桨的水动力性能;导管和螺旋桨均采用基于速度势的面元法,它们间的影响通过相互的诱导速度势数值迭代来体现.与诱导速度体现相互影响的方法相比,本文方法可节省编程及计算时间;对JD系列导管螺旋桨的计算与实验结果的比较表明,该方法可以有效地预估导管螺旋桨的水动力性能. 相似文献