基于振动传递分析的舰船辐射噪声特性研究

基于结构振动传递分析,采用有限元/边界元法,结合统计能量分析,探讨了舰船的辐射噪声特性以及噪声预报方法.通过建立某舰船的振动噪声分析模型,研究了船体在主机激励下的振动响应及其沿船体表面的分布规律.在此基础上,分析了各舱段的辐射声功率对舰船辐射噪声的贡献,并且对主机激励下的全船辐射噪声特性进行了研究及预报.研究工作以及所...     

浅析我国舰船低噪声设备研制及技术的不足

在简要论述舰船低噪声机电设备的军事意义和作用、国外舰船低噪声机电设备技术水平及我国舰船低噪声机电设备研究现状的基础上,着重从研制专业队伍、技术积累、基础理论研究、试验设施、总体设计与设备研制关系、设备研制与振动噪声控制关系、舰船条件的特殊性、低噪声设备加工工艺控制、加工工艺与设备振动噪声之间关系等方面,探讨了我国舰船低噪声设备研制及技术的不足,并提出了我国低噪声机电设备研究的发展方向.     

舰船噪声振动测量中的不确定度评定及控制

通过对舰船噪声振动测量中的不确定度研究，结合多年噪声振动测量的实践经验，对舰船噪声振动测量不确定度产生的原因及控制提出了看法，并通过实例对测量结果的不确定度进行了计算，可供有关人员参考。     

舰船振动噪声的快速预报技术

为了快速预报舰船的机械噪声,采用有限元/边界元法,分析研究不同船型、不同的基座结构及其布置方案以及船体外壳肋骨的不同布置形式对振动传递特性和水下声辐射特性的影响.在此基础上,提出一种舰船机械噪声快速预报方法,并且结合设备振动测试结果,对某舰船在不同工况下的辐射噪声进行了预报.     

舰船辐射噪声特征建模

介绍一种舰船辐射噪声1/3 Oct谱模型建立方法.通过分别对机械噪声、螺旋桨直接辐射噪声及桨轴激励艇体振动噪声的特征规律研究,建立了机械和螺旋桨的额定声压脉动谱模型及桨轴激励艇体响应函数模型.根据机械噪声和螺旋桨噪声同航速的变化关系,得到不同转速下的合成辐射噪声1/3 Oct谱.利用Matlab GUI编写舰船辐射噪声...     

基于水弹性力学的SWATH船结构振动与噪声分析

文章以三维水弹性力学理论为基础,提出了综合考虑波浪与设备机械激励下的船体结构振动分析方法,并对小水线面双体船的船体振动响应特性进行了分析,预报了该船体的固有频率特性,及在试验工况与航行时受发电机激励下的局部结构振动响应,并与实船测量结果进行了对比。结果表明,该方法对于船体总振动、及船体受机械激励作用下的强迫振动分析预报是有效的,可应用于工程设计。同时,利用水弹性方法对SWATH船在波浪中的辐射噪声与近场噪声进行了预报,数值预报结果与试验进行了对比,表明该方法在噪声分析中也是可行的。     

基于有限元分析的舰船轴系尾部结构水声特性分析

近年来,船舶的隐身特性引起了研究人员的广泛关注,尤其对于军事应用的舰船。大量的试验表明,船舶的噪声很大一部分来源于舰船的轴系振动,而轴系作为舰船动力系统的关键部件,其设计和优化本身也具有非常重要的意义。本文研究的重点是舰船轴系的振动与水声特性,运用了有限元分析技术,同时也对舰船的轴系振动进行了数学建模。本文的研究有助于改进舰船轴系的噪声特性,提高舰船的隐身性能。     

隔振器对舰船基座振动特性的影响

为了研究隔振器类型及布置方式对舰船基座振动特性的影响,针对舰船设备普遍采用隔振器与基座相连的连接方式,首先分析了隔振器刚度、阻尼等参数对舰船基座激扰力特性的影响,并以某船舶发电机组为例,基于有限元方法讨论了隔振器类型及布置方式对舰船基座振动特性的影响。研究表明,一方面,设备向基座传递的激扰力与隔振器刚度、阻尼及设备—隔振器—基座系统固有频率等密切相关;另一方面,隔振器类型及布置方式对基座振动特性也有较大影响。当激励频率较低时,隔振器布置方式对基座振动特性的影响相对较小;而当激励频率较高时,隔振器布置方式对基座振动特性的影响则相对较大。     

舰船修理振动噪声测试与评估研究

文章围绕舰船修理期间的振动噪声测试与评估开展了研究,阐述了修理振动噪声评估的原理和方法,分析了振动噪声测试的步骤及要求,在此基础上对某舰船修理前后设备振动状态进行了评估,对振动状态恶化的设备进行了深入研究,提出了声学质量控制措施与建议,为舰船振动噪声整改提供了依据和参考。     

基于传感器的舰船机电设备状态监测

当前舰船机电设备状态监测方法存在许多不足,如监测正确率低、监测过程复杂等。为了改善舰船机电设备状态监测结果,设计基于传感器的舰船机电设备状态监测方法。首先分析舰船机电设备状态监测原理,指出影响舰船机电设备状态监测结果的因素,然后采用传感器对舰船机电设备状态信号进行实时采集,并去除舰船机电设备状态信号的噪声,最后从舰船机电设备状态信号中提取特征向量,并引入支持向量机建立舰船机电设备状态监测模型。与其他舰船机电设备状态监测方法相比,本文方法可以更好地描述舰船机电设备状态,提高了舰船机电设备状态监测准确率,使舰船机电设备状态监测过程更加简单,加快了舰船机电设备状态监测速度,具有更好的实际应用价值。     

Dynamic response of the non-contact underwater explosions on naval equipment

Shock resistance capacity of the shipboard equipment especially for large ones, has been a strong concern of navies all over the world for a long time. The shipboard equipment have previously generally been studied separate from hull structure before. In this paper the coupling elastic effect between equipment and hull structure is taken into account. With the ABAQUS software, the integrated model of the equipment coupled with the hull structure is established to study the dynamic response of the shipboard equipment to the shock wave load as well as the bubble pulsation load. In order to verify the numerical method, the simulated results are compared to the experimental data, which are from a specific underwater explosion on an actual ship. On this basis, by changing the charge location, attack angle, equipment installation location and other parameters, the characteristics of dynamic response under different conditions can be obtained. In addition, the results of the integrated calculation and the non-integrated one are compared and the characteristic parameters which affect the equipment shock response are analyzed. Some curves and conclusions are obtained for engineering applications, which provides some insights into the shock resistance of shipboard equipment.     

舰艇声呐系统集成探讨

舰艇声呐系统集成是当前舰船电子研究领域的新热点,同时它也是一项复杂的系统工程。分析国内外舰艇声呐的发展过程和趋势,从舰艇平台、作战系统、声呐设备几方面对舰艇声呐设备集成概念等进行研究、探讨,提出了舰艇声呐功能、结构、信息一体化集成建议。     

MS Project软件在舰船设计中的应用初探

结合舰船装备设计的流程和特点，分析当前舰船装备设计管理上存在的问题，应用MS Project软件建立舰船装备船机电方案设计项目管理的初步模型，给出设计过程的甘特图．并运用该模型就任务脱期、资源调配等因素对项目整体计划的影响进行分析和快速重构．证明在舰船装备设计中灵活运用MS Project等软件能改善传统经验管理模式的不足，提高管理效率，有利于舰船装备设计项目的精细化管理。     

双波冲击机在减振器冲击试验中应用的可行性分析

简单介绍了冲击试验机的发展概况,重点讨论了双波冲击机的优越性及其在橡胶减振器等船舶设备冲击试验中应用的可行性。利用现有双波冲击机中正波和负波发生系统的数学模型,数值仿真了冲击机的输出波形特征。分析了双波冲击机的试验条件,计算了冲击机在空载工况下的冲击响应谱。仿真结果表明,双波冲击机的冲击响应谱在允许误差范围内,冲击机输出波形符合标准,可以用于冲击试验。     

舰船装备可靠性分析评估程序及实施方法研究

介绍了舰船装备可靠性评估的特殊性,以及进行舰船装备可靠性评估的程序、方法以及数据处理、评估时遵循的原则及工程实施的约定,并结合舰载作战系统的工程实际,对相关程序及方法进行了举例说明。     

舰艇设备抗冲击技术研究

文章介绍了国外舰船设备抗冲击研究的历史和动态,以及国内抗冲击计算研究现状,并针对目前国内在抗冲击研究中存在的不足,提出了一些建议,可供舰船设备隔振系统非线性抗冲击研究参考。     

现代海战中舰载电子设备毁伤程度与修复能力的评估算法

为了保障水面舰艇具有可持续作战能力,实现舰载电子设备的快速修复,研究现代海战中舰载电子设备毁伤程度与修复能力的评估算法是非常必要的。论文采用定性分析与定量计算几何的方法,首先介绍了现代海战中舰载电子设备遭受毁伤的因素,然后给出了舰载电子设备遭受毁伤程度、抢修工作量和抢修能力的定量评估算法。具有一定的实用价值。     

舰载通信系统电磁兼容问题及控制

受空间条件限制,舰载通信系统的大量收发信设备被密集配置于狭小空间内,使系统处于自身强电磁辐射作用的环境之中,容易引发电磁兼容问题。文章分析了影响舰载通信系统正常工作的几类干扰作用,探讨了系统电磁兼容性能控制问题。     

Developing a marine engineering centre of excellence for competency-based training

Institutes imparting training in marine engineering require replication of shipboard ambience for strengthening the competencies. For building an engineering centre for training, five options at different physical levels were considered based on a model of a new liquefied natural gas tanker ship build. A mock-up facility, simulator, full-scale engine room, scaled down version and a combination arrangement with live and dummy equipment were the options. Analytic hierarchy process was applied for selecting a suitable option based on criteria of cost, effectiveness in attaining competencies, practicability and environmental conduciveness. Analyses were carried out on the eigenvalues based on eight subselection criteria. The combination of live equipment (boilers and turbo alternator) and non-live shipboard equipment (auxiliaries) was chosen based on the global weightages obtained from the pairwise comparison matrix computations. The reliability was ascertained from the consistency index which was less than 0.1. For selection of the learning modes and the equipment, a constructivist approach of learners reflecting and choosing the learning mode was adopted. Industry practitioners were made into learner groups composed of trainers, shipboard personnel and company personnel. Established competencies were assigned as scores to the different learning modes. ANOVA application and statistical methods were used to analyse the scores to verify if there were too much variation in the choices. The calculated F ratio values were low (0.14 to 0.40) compared to the reference values indicating that the choices were even. The chi-squared test indicated that the group composition did have an influence on choosing the learning mode and equipment for training. The objective of identifying the learning mode and equipment for the training centre was achieved.     

Numerical simulation of the anti-shock performance of a gear case

Both sea battles and testing of ship in underwater explosions reveal unacceptably poor anti-shock performance of important shipboard equipment. Anti-shock performance of shipboard equipment is a significant factor determining fighting strength and survivability. The anti-shock performance of a shipboard gear case based on BV043/85 was investigated using numerical simulation. A geometric model of the gear case was built using MDT software and meshed in HyperMesh software, and then the finite element model of the gear case was formed. Using ABAQUS software, the anti-shock performance of the gear case was simulated. First, shock response of typical regions of gear case was determined. Next, some generalizations were made about the anti-shock performance of the gear case by analyzing the Mises stress of typical regions varied with shock inputs. Third, weak regions were determined from simulation results. The threshold values of shock resistance of the gear case at different impulse widths were obtained through interpolating the numerical simulation results selected from the most dangerous spot. This research provides a basis for further optimization of the design of gear cases.