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在介绍遗传算法思想以及目前于工程结构优化计算应用的基础上,对遗传算法在其它方面的优化计算思想进行总结,并认为这些优化计算思想也可以应用在工程结构的优化计算中,用以提高遗传算法在工程结构优化计算中的优化效果。 相似文献
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网壳结构的极限承载力取决于网壳结构的稳定性.结构线性计算比较简单,而结构非线性的计算则比较复杂.据此,分析了凯威特球面网壳结构的线性过程,并对两类计算结果分析比较得出两者之间的定量关系式. 相似文献
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传统的船体结构总纵强度梁理论计算一般是基于对称的船体横剖面,文中提出了不对称船体结构梁理论弯曲正应力的计算方法,并选取样船作为算例,结合有限元计算进行弯曲正应力对比分析,验证梁理论计算的准确性。同时对比将不对称结构视为对称结构时的梁理论计算总纵弯曲正应力,提出不对称结构对总纵强度的影响。 相似文献
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本文阐述了结构强度计算有限元法的基本原理,结合110000DWT油船尾部拖桩的局部结构加强计算过程,概括了应用有限元法进行局部结构强度计算的一般步骤和要点。 相似文献
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桁架式结构因型式和载荷的多样性,其结构计算一直以来是一个难题,因此采用有限元计算方法计算校核打桩船桩架在海上作业和拖航工况时的强度和稳定性,为船舶桁架式结构计算提供了一种化繁为简的方法。 相似文献
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根据第一代40万吨超大型矿砂船(VLOC)的状况勘验情况,对船舶的典型布置和结构特点进行概括,并对船舶的典型结构缺陷进行总结。基于结构特点和运营中的结构受力情况,对典型结构缺陷进行分析。基于分析结果,对典型结构缺陷的处理措施进行介绍。根据现有结构状态,提出结构检验注意要点,为第一代40万吨VLOC的后续结构检验提供指导,也为即将投入运营的第二代40万吨VLOC的结构检验提供参考,以有针对性地对40万吨VLOC进行结构检验,提高结构检验效率。 相似文献
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船舶结构高阶动力分析的模型简化方法研究 总被引:1,自引:0,他引:1
针对船舶结构动力分析的模型简化条件及方法进行研究,通过讨论阻尼对结构动力响应分布的影响,从波动角度研究了以局部结构代替整体模型进行动力分析的模型简化条件,提出了船舶结构高阶动力分析模型简化的行波法.研究表明,阻尼可降低结构的动力响应,并使结构动力响应随距激扰力作用点的距离呈指数函数衰减;结构动力模型能否简化很大程度上取决于阻尼、激扰频率及结构物理参数等条件,激扰力在简化模型与原结构中产生的弯曲波传播距离相差整数倍波长时,简化模型的动力响应可最大限度地与原结构保证一致,进而提出了均质结构及板架等复杂结构动力分析的模型简化定量方法一行波法;并采用算例验证了其有效性. 相似文献
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海上极端波过去常常导致船舶结构的极限破坏,而船舶的极限崩溃涉及到船体结构的动态极限强度和结构非线性.该文通过二维的水弹塑性方法研究了集装箱船在极端波中的非线性动态强度,该方法考虑了船体的极限强度以及船体结构的非线性和波浪之间的耦合.并通过该二维水弹塑性方法和极限评估方法研究了船体结构的结构优化.文中还通过二次规划法(SQP)来优化基于非线性的动态强度的集装箱船体结构.最少的结构成本是本优化的目标函数,约束条件保证船体的强度要小于结构的极限强度,并且结构设计尺寸要满足规范的要求.随着设计波高的变化,这些优化的设计变量的变化趋势得以发现,一些研究的结论可用于船舶规范的参考. 相似文献
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Undoubtedly, the main advantage of the additive manufacture technology is to allow building miniature structural parts with a large degree of complexity such as to replicate structural details of real-scale marine structures. This work presents a new technique for reproducing the structural response of large-scale thin-walled metallic structures when subjected to crushing loadings by using scaled-down additive manufactured models. This technique couples scaling laws for strain rate sensitive materials and a thickness distortion technique based on the structural collapse mode. In order to validate this coupled technique, the structural response of a large-scale crushing test of a web girder structure was experimentally replicated by using a 1/40 scale reduction model. The results and conclusions summarize the prospects and limitations of additive manufacturing of miniature complex marine structures for structural purposes and crashworthiness verification. 相似文献
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A common approach to investigate the response of a structural detail such as a hatch corner is to compute the seakeeping loads using a linear 3D Boundary Element Method (BEM) and transfer the seakeeping loads to a Finite Element (FE) model of the ship structure. This approach is suitable for computations of the fatigue loading of structural details near amidships because a majority of the fatigue loading will occur in mild sea-states where the loading may be assumed linear. However, the linear seakeeping model may not hold when one investigates the ultimate response of the local bow structure of a ship which is designed to remain operational in severe conditions, for example, a frigate. A linear seakeeping analysis will significantly underpredict the loading at the bow because both the impulsive slamming loads and the non-linearities in the non-impulsive wave loads will contribute significant to the structural loading.The non-linear loads require one to first derive a short-term distribution of the local structural response before the ultimate value of the response can be derived. A method to compute the short-term distribution of a structural detail is presented in this paper. The first step is to perform seakeeping analyses which includes slamming, non-linear Froude-Kryloff and hydrostatic loads. The short-term distribution of the total hydrodynamic loading at the structural detail is obtained by simulating the seakeeping response for several hours. The response of the local structure is computed for the most severe impacts found in the seakeeping simulation. The hydrodynamic loading, including the non-linear contributions, is transfer to the structural model and the structural response is computed using the FE-method. The results of the structural analyses allow one to transform the short-term distribution of the structural loading to a short-term distribution of the response of the structural detail. A designer can obtain the ultimate structural response by entering the probability at which one accepts overloading of the structure in the short-term distribution of the response of the structural detail. 相似文献
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船体结构耐撞性优化设计的主要目的是在船舶碰撞研究的基础上对结构进行优化设计,提高船体结构的耐撞性能。基于正交试验设计、BP神经网络和遗传算法,形成了船体结构耐撞性能优化设计方法。提出了一种耐撞性综合指标,并以此指标作为优化的目标函数,以结构质量为约束条件,利用MSC/Dytran有限元软件对船舶碰撞进行数值仿真,完成对某船舷侧结构进行耐撞性优化设计,结果表明优化过后结构耐撞性能有较大提高,这为结构耐撞性能优化设计提供了一种新的思路和方法。 相似文献
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B. Rapo 《Marine Structures》1988,1(3):189-217
The structural analysis based on application of numerical methods used in the solution of complex structural problems, when applied correctly, is a powerful tool leading to rational structural design of ships. This paper discusses the practicalities of its application and indicates that in order to achieve the stated objective, the following are essential pre-requisites: a) full understanding of the problem; b) ability to solve the problem using currently available methods; and c) ability to interpret the results of the analysis correctly. Whilst there is still a lot of discussion on whether the structural analysis represents a structural design or a structural verification tool, the view expressed in this paper is that the structural analysis should mainly be used in the latter context. This means that a sound engineering solution ought to be established in the first phase of the analysis and used as a basis. The final results will then only be used to perfect the structural detail and modify the areas where rapid stress gradients occur. Any other approach would invariably require repetitive, time consuming and costly iterations which under normal circumstances may prove to be counter-productive. This paper presents a few examples of practical application, the methodology of achieving the solution and the way of interpreting the results. 相似文献
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基于Autodesk平台的BIM技术在水运工程结构设计中缺少一款与建模软件Revit匹配的结构计算软件,为此提出一种将通用有限元结构计算软件ANSYS与Revit耦合的方法。由于Revit仅在族环境中才能建成水运工程参数模型,所以先对Revit基础图元类型进行编程分类,把可载入族赋予结构属性。采用Revit API技术过滤结构模型的几何信息、属性信息、材质信息,再将提取信息编译成ANSYS命令流文件,实现结构计算软件ANSYS与BIM建模软件的数据转换,并依据Revit布尔算法优化ANSYS结构计算前处理的映射网格划分步骤。最后使用某船闸主体工程进行验证,证明本方法在结构计算中运用是可行性的。 相似文献