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基于蒙特卡罗模拟的船体型线稳健优化设计 总被引:2,自引:0,他引:2
《江苏船舶》2016,(3):1-6
传统的船型优化仅考虑了确定性因素的影响,忽视了设计和使用中不确定性因素的存在,常导致船型方案不可行或航行性能较差。为了考虑不确定因素对船舶阻力性能的影响,在船型优化中引入稳健优化设计理论。首先,阐述了稳健优化设计的基本原理,在此基础上,以KCS船型为例,考虑了航速不确定性的影响,建立了稳健优化数学模型。其次,基于Isight平台完成了KCS船体型线稳健优化设计。试验结果表明:船体型线稳健优化设计可有效地减小船型方案失效的可能性,更符合工程实际。 相似文献
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基于Isight优化软件和通用有限元软件,以扒杆重量为目标函数,采用粒子群算法(PSO)和遗传算法对某起重船扒杆结构进行了优化设计,并讨论了PSO算法的稳定性。通过对两种算法优化结果的比较分析表明,PSO算法优化效果好,收敛速度快,且计算稳定性高,验证了PSO算法在工程船舶结构优化设计中的有效性。 相似文献
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[目的]舰船舵体结构在舰船航行中不可避免地会发生振动,有必要通过合理的优化设计来使舵体结构的一阶固有频率避开其工作频率。[方法]为此,从3个方面讨论复合材料舵一阶固有频率的优化设计问题,基于有限元软件ABAQUS完成复合材料舵的仿真分析,并在给定初始设计参数后再计算初始的一阶固有频率。首先,开展骨架布局的规律分析,通过对照10组骨架布局形式下的固有频率大小,确定较优的骨架形式;然后,基于Isight优化软件,运用梯度算法NLPQL对纵、横骨架厚度进行优化分析;之后,同样采用Isight软件,基于LSGRG算法对蒙皮的铺层厚度进行优化;最后,通过对照10种铺层顺序形式,确定较优的铺层顺序。[结果]优化计算结果显示,复合材料舵的一阶固有频率相比初始方案提升了169.19%,同时重量下降了16.63%。[结论]表明所采用的优化思路和方法对于复合材料舵一阶固有频率的优化是可行的,并能获得令人满意的设计方案。 相似文献
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《中国舰船研究》2016,(6)
基于标准的协同优化算法,针对其对初始点敏感、收敛慢等固有缺陷,将协同优化算法法与混合优化算法及动态松弛法相结合,提出分段动态松弛协同优化算法,并将其应用到船舶机舱结构多目标优化问题中。针对船舶主机舱结构静、动态多学科多目标优化问题,建立主机舱结构的多目标协同优化模型。在Isight优化软件中采用改进的分段动态松弛协同优化算法,对船舶机舱结构进行静、动态多学科多目标协同优化设计,得到优化设计的最优解。优化结果表明,相对于基于遗传算法的协同优化算法,分段动态松弛协同优化算法兼顾了优化的高效性和准确性,对于实际工程中更加复杂的多学科多目标结构优化具有一定的参考价值。 相似文献
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建立了分布载荷作用下四边固支复合材料帽型加筋壁板弯曲变形的理论模型。通过算例比较理论计算和有限元仿真的结果,验证了理论模型的可靠性。在该理论计算模型的基础上,借助优化软件Isight,开展铺层角度和几何尺寸对目标函数的灵敏度分析,寻找主要设计变量并开展其对目标函数影响的研究以及加筋壁板刚度的优化设计。研究结果显示,面板和帽形筋外侧的铺层角、帽形筋高度以及斜边与面板的夹角是影响加筋壁板弯曲刚度和挠度的主要变量;加筋壁板弯曲刚度优化的主要方向是提高纵向弯曲刚度系数。对于同一优化目标,借助Isight平台可得到多种优化方案,工程设计人员可根据具体需求从中选择合适的方案。 相似文献
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浮筏系统隔振优化设计 总被引:1,自引:0,他引:1
文中基于Abaqus瞬时模态动态分析获得浮筏系统动力响应,对多激励源浮筏建立了隔振性能优化设计数学模型。选取筏架板厚、隔振器刚度、设备布局坐标作为设计变量,考虑设备布局、筏架应力、质量以及工艺性要求等约束,以浮筏基座处的力振级落差为目标函数,采用Python建立浮筏有限元分析参数化模型,通过Isight平台集成Abaqus,运用遗传算法,给出了浮筏设备隔振性能优化设计最优解。 相似文献
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采用Patran/Nastran对车渡船跳板结构进行强度分析,在此基础上,集成Isight/Nastran对车渡船跳板结构进行优化设计。以结构质量为目标,跳板面板相当应力、跳板骨材合成应力及跳板结构位移为约束条件,重点考虑跳板面板厚度、跳板普通横梁以及跳板纵桁和强横梁的截面尺寸。最后,采用Isight中自带的多岛遗传算法(MIGA)对某渡船跳板结构进行优化,使得该跳板在最大等效应力不超过许用值的同时总质量达到最小。优化后跳板结构质量为7 368 kg,比之前的质量9 477 kg减少了22.25%,优化效果明显,且满足强度和刚度要求。 相似文献
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散货船和油船共同结构规范(CSR)规定了船体梁总纵强度、局部强度、屈曲强度、疲劳强度等要求。目前,对油船中横剖面结构尺寸优化的研究较多,但设计约束条件通常比较简单,较少考虑CSR中的多种约束条件和载荷,因此优化结果的实用性有待商榷。由于CSR规范条文较繁琐且不断更新,考虑利用船级社规范校核软件进行符合描述性要求的规范计算,在通用优化平台Isight中集成Mars2000软件,实现剖面尺寸自动优化。根据上述优化思路和流程,开发了基于Excel-Mars2000-Isight平台的油船中横剖面结构优化工具。 相似文献
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In this paper, a hybrid automatic optimization strategy is proposed for the design of underwater robot lines. Isight is introduced as an integration platform. The construction of this platform is based on the user programming and several commercial software including UG6.0, GAMBIT2.4.6 and FLUENT12.0. An intelligent parameter optimization method, the particle swarm optimization, is incorporated into the platform. To verify the strategy proposed, a simulation is conducted on the underwater robot model 5470, which originates from the DTRC SUBOFF project. With the automatic optimization platform, the minimal resistance is taken as the optimization goal;the wet surface area as the constraint condition; the length of the fore-body, maximum body radius and after-body's minimum radius as the design variables. With the CFD calculation, the RANS equations and the standard turbulence model are used for direct numerical simulation. By analyses of the simulation results, it is concluded that the platform is of high efficiency and feasibility. Through the platform, a variety of schemes for the design of the lines are generated and the optimal solution is achieved. The combination of the intelligent optimization algorithm and the numerical simulation ensures a global optimal solution and improves the efficiency of the searching solutions. 相似文献
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In this paper, a hybrid automatic optimization strategy is proposed for the design of underwater robot lines. Isight is introduced as an integration platform. The construction of this platform is based on the user programming and several commercial software including UG6.0, GAMBIT2.4.6 and FLUENT12.0. An intelligent parameter optimization method, the particle swarm optimization, is incorporated into the platform. To verify the strategy proposed, a simulation is conducted on the underwater robot model 5470, which originates from the DTRC SUBOFF project. With the automatic optimization platform, the minimal resistance is taken as the optimization goal; the wet surface area as the constraint condition; the length of the fore-body, maximum body radius and after-body's minimum radius as the design variables. With the CFD calculation, the RANS equations and the standard turbulence model are used for direct numerical simulation. By analyses of the simulation results, it is concluded that the platform is of high efficiency and feasibility. Through the platform, a variety of schemes for the design of the lines are generated and the optimal solution is achieved. The combination of the intelligent optimization algorithm and the numerical simulation ensures a global optimal solution and improves the efficiency of the searching solutions. 相似文献
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螺旋桨是目前船舶及海洋装备重要推进装置,其工作可靠性及服役性能对我国海洋战略的实施具有非常重要的意义。复杂海洋环境下螺旋桨服役性能除受到风、浪、流等环境因素影响外,还受到周围其他海洋异物的影响,进而引起螺旋桨载荷特性发生突变。本文基于计算流体力学基础理论,建立导管螺旋桨水动力学数值仿真模型。将海洋异物接近过程简化为准定常过程,分析不同接近距离对导管桨水动力性能的影响。基于流固耦合理论,将水动力学载荷施加在桨叶表面,获得不同接近距离时桨叶应力、应变的变化特性。研究结果表明:海洋异物的接近会对导管桨水动力学特性产生较大的影响作用。当异物接近距离为0.01 m时,导管桨推力将增加11.74%,扭矩增加12.73%,桨叶最大应力值增加32.06%,最大形变量增加30.28%。本文研究工作对导管桨服役性能评估及疲劳寿命预测具有非常重要的参考意义。 相似文献
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The hydrophysical and hydrochemical structure of the Sea of Azov, with developed bottom anoxia, was studied during the RV “Akvanavt” cruise from July 31 to August 03, 2001. The anoxic zone with a thickness from 0.5 to 4 m above the bottom was found in all deep regions of the Sea. Concentrations of hydrochemical parameters were similar to the pronounced anoxic conditions (about 90 mmol m− 3 of hydrogen sulfide, 17 mmol m− 3 of ammonia, 6 mmol m− 3 of phosphate, 7 mmol m− 3 of total manganese). The hydrophysical structure was characterized by the uniform distribution of temperature in the upper 6–7 m mixed layer (UML). Below this a thin (0.4–0.8 m) thermocline layer was observed, just above the anoxic waters. Formation of this phenomenon was connected with that summer weather conditions. Intensive rains led to increased influx of river waters in June. That resulted in large input of allochtonous organic matter (OM) and inorganic nutrients; the latter were consumed on the additional autochthonous organic matter production. In July the weather was characterized by a significant rise in the daily averaged air temperature and large oscillations of temperature during the day. In this period a wind of constant direction was absent, but wind bursts were observed. The completed analyses showed that the formation of such a structure could be connected with the following factors: (i) positive growth trends of the daily averaged temperature and the daily oscillations of temperature, (ii) presence of wind bursts. The joint action of these factors resulted in the formation of the UML. The amplitude of wind bursts determined the depth of UML, and the value of trend determined the value of the temperature change in the thermocline. An initial presence of bottom halocline (caused by the Black Sea water influx to the bottom of the Sea of Azov) prevented the heating of the bottom layer and therefore led to an increase of vertical gradient of temperature in the thermocline. The spatial distribution of the turbulent exchange coefficient confirmed the existence of a “stagnation” area located above the anoxia zone, which is also, apparently, the reason for its occurrence. 相似文献
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本研究优化船舶推进轴系孔径比的取值范围,使轴系的综合力学性能达到最理想的状态,目的是在船舶设计时,帮助船舶设计者快速确定轴系的最佳孔径尺寸。文章以某散货船的轴系为研究对象,在考虑船舶螺旋桨偏心力的情况下,建立了轴系危险截面的等效应力和抗扭强度的数学模型,运用ANSYS有限元分析软件,对不同孔径比艉轴的危险截面的等效应力和抗扭强度进行了对比分析,并且进行了校中情况对比分析研究。将理论值和实测值进行对比,发现理论值和实测结果拟合的非常好。经过对比研究发现,船舶轴系的综合力学性能比较优越的孔径比范围是0.21~0.28,在此范围内,轴系校中效果也比较好。该研究方法为船舶轴系的设计提供了分析依据。 相似文献