共查询到20条相似文献,搜索用时 140 毫秒
1.
基于有限元的功率流计算及隔振系统优化设计技术研究 总被引:11,自引:4,他引:7
振动功率流法是研究柔性结构动态特性的有效手段,导纳功率流分析法是目前的主要研究方法,由于只能得到极少数简单结构的解析导纳,对于复杂的结构导纳功率流分析法束手无策.有限元动态分析可以解决绝大多数结构的振动问题,目前大多数有限元动态分析主要集中于模态分析、位移响应分析等.本文从有限元动力方程推导出发,给出了节点频域复数力的表达式,进而给出基于有限元动力分析的功率流计算方法.对一个单梁隔振系统进行理论计算和有限元计算对比,验证了该方法的准确性.最后,基于该方法对隔振器参数和振源布置位置寻优,得到最优参数使传递到基础的振动能量最小.这种方法对大型结构动态设计具有借鉴意义,可应用到工程实际中. 相似文献
2.
船体结构有限元计算结果可视化系统的设计与实现 总被引:1,自引:0,他引:1
基于图形平台OpenGL开发了船体结构有限元计算结果可视化系统(CCS-FEVS)。本文阐述了船体结构有限元计算结果可视化系统的设计思路、系统结构、数据管理及其多种处理和显示数据场的方法,并给出了实例。 相似文献
3.
船体结构强度直接计算中的外载荷节点化方法 总被引:3,自引:1,他引:2
在船体结构强度直接计算方法中,需要建立三维有限元模型,船体所受到的外载荷也应相应地转化为有限元节点力。本文给出了外载荷节点化的方法并编制相应的程序,用于船舶直接设计计算中。 相似文献
4.
采用有限元和边界元方法分析弹性加肋圆柱壳的声学相似性 总被引:15,自引:1,他引:14
本文采用有限元和边界元方法,分析水下运动体的典型结构──有限长弹性加肋圆柱壳的振动、耦合振动和声辐射的相似性,给出这种结构的声学相似条件和相似关系。 相似文献
5.
集装箱船舱口角隅应力集中系数的有限元分析的精度 总被引:2,自引:0,他引:2
集装箱船舱口角隅的应力集中是船舶结构强度的一个重要问题。随着有限元技术的发展,目前舱口角隅的应力集中系数大都可以通过有限元计算直接获得。由于有限元分析过程中存在着大量不确定性,通过控制其有限元分析各个步骤的质量来保证有限元分析的精度,已经成为一个重要的研究方向。本文利用现有有限元分析软件(ABAQUS),通过对不同模型简化方法的讨论,给出了正确计算舱口角隅结构应力集中系数的模型简化方法,并在此基础上讨论了网格尺度对应力集中系数的影响。 相似文献
6.
本文对推进电机端盖进行了机械结构优化设计.首先给出数学模型指出了数学本质,然后给出通过大型有限元分析软件ANSYS中APDL语言来实现优化的方法,在优化计算分析后,进行较详细的讨论. 相似文献
7.
纵骨穿过舱壁板的开孔应力集中系数 总被引:2,自引:0,他引:2
疲劳裂纹各方面一往发生在船舶结构的局部高应力区,而疲劳分析结果通常取决于任何准确确定结构的应力集中系数,本文研究为铺设纵骨而在舱壁板上开孔的应力集中,采用有限元方法对预先给定的结构进行应力分析。基于有限元计算结果给出了舱壁板典型开孔(参见ABS油船规范)的应力集中系数表。 相似文献
8.
9.
利用MSC/PATRAN、MSC/NASTRAN对38In双体甲板货船总体结构强度进行了有限元强度计算。给出了外载荷的计算方法和边界条件的施加方法,并在11种工况下对38m双体甲板货船进行了总体结构强度有限元分析。通过有限元分析得到的结论可用于双体甲板货船设计与优化。计算结果表明结构强度满足强度要求。 相似文献
10.
11.
12.
13.
14.
15.
With increases in ship size and speed, shipboard vibration becomes a significant concern in the design and construction of vessels. Excessive ship vibration is to be avoided for passenger comfort and crew habitability. In addition to the undesired effects on humans, excessive ship vibration may result in the fatigue failure of local structural members or malfunctioning of machinery and equipment. The propeller induces fluctuating pressure on the surface of the hull, which induces vibration in the hull structure. These pressure pulses acting on the ship hull surface above the propeller are the predominant factor for vibrations of ship structures are taken as excitation forces for forced vibration analysis. Ship structures are complex and may be analyzed after idealization of the structure. Several simplifying assumptions are made in the finite element idealization of the hull structure. In this study, a three-dimensional finite element model representing the entire ship hull, including the deckhouse and machinery propulsion system, has been developed using solid modeling software for local and global vibration analyses. Vibration analyses have been conducted under two conditions: free–free (dry) and in-water (wet). The wet analysis has been implemented using acoustic elements. The total damping associated with overall ship hull structure vibration has been considered as a combination of the several damping components. As a result of the global ship free vibration analysis, global natural frequencies and mode shapes have been determined. Moreover, the responses of local ship structures have been determined as a result of the propeller-induced forced vibration analysis. 相似文献
16.
Ship structures may be subjected to repeated random patch loads at different locations. Under these circumstances, ship plates will have large accumulated permanent deformations, which will result in some serious negative effects on their work and safety performance. Therefore, the elasto-plastic response of ship structure under repeated patch loads at different locations are studied by using finite element method. The permanent deformations of plate in the whole loading and unloading process are investigated. In addition, the residual stress and plastic strain states of the panel and stiffeners are studied based on a typical wheel-on-deck interaction scenario. Moreover, according to Hughes's hypothesis, the equivalent method between repeated patch loads at different locations and full uniform pressure load is studied. Considered the influence of plate slenderness, the improved formula for equivalent load coefficient is proposed, showing a good correlation with experimental data and numerical results. The proposed equivalent method can be used for estimating the permanent deformations of ship structures under repeated patch loads at different locations in ship life. 相似文献
17.
18.
19.
20.
离心水泵是舰船上面重要的流体机械,广泛应用于船舶冷却系统、舱底压载系统、循环水系统及消防系统。同时离心泵也是舰船管路噪声源之一,影响着船舶运行环境舒适性与舰船的安全隐蔽性。本文利用fluent软件计算流场非定常过程中叶轮所受时域脉动压力,并提出优化方案。将其作为激励源加载到水泵电机有限元模型上,采用隐式有限元法计算泵组表面振动速度与机脚处加速度,估算泵组振动烈度。将有限元振动速度导入Virtual.Lab软件,采用声学边界元计算泵组的空气噪声辐射。计算结果表明,泵组出水口处与机脚处振动噪声较大,应采用相关的减振降噪技术。 相似文献