【作者】 耿瑞光；

【导师】 张洪田；

【作者基本信息】 哈尔滨工程大学 ， 动力机械及工程， 2011， 博士

【摘要】 气垫船的结构特点,使船体-推进轴系在复杂海洋环境中的耦合问题进一步明显。由于船体-轴系耦合振动问题的复杂性,传统的船舶推进轴系的研究方法大多建立在刚性船体或船体静态变形的基础上,忽略了轴系和船体之间的耦合联系,无法满足气垫船推进轴系动力学特性的研究。因此,从船体-推进轴系整体运动的角度出发,进行气垫船推进轴系动力学特性研究,对于气垫船的发展具有重要意义。本文在系统论述轴系及船体振动、复杂海洋环境激励和虚拟样机技术发展概况和研究现状的基础上,应用现代虚拟样机技术,围绕气垫船推进轴系动力学特性问题,进行了详细研究。论文具体内容包括以下几个方面：1.针对气垫船推进轴系的结构特点,详细阐述有限元、模态综合法、多体动力学和优化理论等虚拟样机技术的支撑理论,并对刚柔耦合系统多体动力学分析的计算方法进行了分析；2.根据气垫船推进轴系的结构特点,提出了一种基于虚拟样机技术,融合多体系统运动学、动力学理论、计算机实体建模和多领域仿真技术,面向系统整体运动的船体-轴系动力学特性研究方法；3.对包括柔性船体、轴段、支承系统、弹性联轴器和减速箱在内的气垫船推进轴系虚拟样机建模方法进行了详细研究。对船体Timoshenko离散建模方法和有限元方法建模进行了比较；对标准化、系列化的齿轮减速箱的参数化建模和虚拟装配问题进行了分析,并对直齿轮副和斜齿轮副的接触刚度进行了研究；4.通过简化的单轴-弹性支承系统和多段轴-弹性支承系统虚拟样机动力学模型,采用正弦载荷扫频进行了系统的频响特性分析,全面研究了轴-弹性支承系统在基础受不同位移激励、不同相位和激励频率下的轴系的动力学响应问题,比较了刚性轴-弹性支承系统和弹性轴-弹性支承系统的区别,得到了相应的结论；5.通过在虚拟样机环境中建立船体实时变形的状态变量,建立了船体-轴系耦合运动的动力学模型。通过简化的船体-多段轴-弹性支承动力学模型,对影响轴承支承力的因素进行了仿真研究；6.运用本文提出的基于虚拟样机技术的船体-轴系动力学特性的研究方法,通过结构拓扑分析,建立了气垫船推进轴系实验装置的虚拟样机仿真模型。对推进轴系中减速齿轮箱、中间轴等进行了多种工作状态下的动力学特性研究,取得的结论对实船的研究工作具有相应的指导意义；7.对影响推进轴系动力学特性的推进桨激励力和波浪载荷对船体的激励作用进行了详细研究,运用船体运动响应的频域研究方法,确定了频域研究中船体运动响应频响函数的求解方法,通过线性波浪叠加法构造了给定海浪谱下的随机波浪时域模型和海浪波面角时域模型,该时域模型可为进一步的实船船体运动分析提供激励输入；8.对气垫船推进轴系进行了优化设计研究。分析了气垫船推进轴系优化设计中目标函数、设计变量和约束函数的选取问题。采用虚拟样机参数化建模方法,结合海浪激励的分析结果,应用广义缩减梯度法对砰击海情下气垫船推进轴系进行了结构优化；9.首次提出了一种能模拟复杂海洋环境的激励可控的柔性基础轴系推进系统实验装置的设计思想,设计建造了柔性基础-推进轴系实验装置。该实验装置可作为气垫船推进轴系动力学特性研究有效的实验验证平台。在此实验装置上进行了气垫船推进轴系的实验研究。实验研究表明,本文所提出的基于虚拟样机技术的气垫船推进轴系动力学特性的分析方法是有效和正确的。最后,对本文的主要创新点进行了归纳评述,并对进一步的研究方向提出了作者的一些看法。更多还原

【Abstract】 Because of structure characteristics of hovercraft, coupling problems of ship hull-shafting were more and more obvious under action of complex sea excitement. Traditional research methods of ship shafting were based on rigid ship hull or static deforming of hull because coupling characters was very complex between ship shafting and ship hull. These simplified methods sever connection between shafting and hull. At present, effective study method still is absent to coupling characters study between shafting and ship hull acted by complex environment. So, how to solve the dynamics problems of hovercraft’s propulsion shafting is significative to development of hovercraft.In the dissertation, present study state of vibration of shafting and ship hull, excitation of complex ocean wave and virtual prototyping were systematically discussed. On the base, dynamics problems of hovercraft were studied particularly applied modern virtual prototyping. The main contents of the dissertation are as follows.1. According to structures characteristics of hovercraft’s propulsion shaftig, basic theories of virtual prototyping were studied particularly including FEM, modal synthetic method, multi-body dynamics and optimization theory. In addition, numerical calculation method to analyze multi-body system comprised rigid bodies and flexible bodies were studied.2. According to structure characteristics of hovercraft’s propulsion shaftig, a research method that study dynamics characteristics of ship hull-shafting was put forwarded based on virtual prototyping combining muli-body dynamics, solid modeling of computer and multi-field simulation.3. Virtual prototyping of hovercraft’s propulsion shaftig comprised flexible ship hull, shaft, bearing systems, elastic couplers and gearbox was studied particularly. Discrete modeling method of ship hull applied Timoshenko elastic beam was compared with modeling method of ship hull applied FEM. Elastic bearing’s modeling method and elastic coupler’s modeling method were determined in virtual prototype. Parameterize modeling of gear and virtual assembly of gearbox were studied, and contact stiffness of straight gear pair and helical gear pair was studied too. 4. Virtual prototypes model of single shaft-elastic bearing system and model of multi-shaft system were established. These model’s frequency response characteristics were analyzed through sine sweep-frequency method, and shafting dynamic responses were studied when foundation of shafting-elastic bearing system was excited by displacements excitation of variant frequency, variant phase and variant displacement amount. And corresponding conclusions were obtained. According to above problems, differences were compared between rigid shaft-elastic bearing system and elastic shafting-elastic shafting system.5. Through creating state variables of real-time deforming of ship hull, dynamic model of coupling system of ship hull-shafting was established in virtual prototype environment. Through simplified dynamic model of ship hull-multi shafts-elastic bearing, factors to influence bearing force were studied.6. Applied the modeling and studied method of ship hull-shafting system that been put forward in the dissertation, simulation model of experimential facility of hovercraft’s propulsion shafting was established through structure topology analysis. Some part’s dynamics characteristics were obtained including gearbox and middle shaft through simulation research. These research conclusions could have directive effects to research of actual ship.7. Excitement effect of sea wave acted on propeller and hull were introduced、Applied frequency domain analysis method to movement response of ship hull, solution method of frequency-response function of movement of ship hull was determined. Time domain model of random wave and time domain model of wave surface angle were synthesized through linear wave superposition method. These time domain model could be farther excitement import to movement analysis of actual ship.8. Hovercraft’s propulsion shafting was as specific study object, how to select objective functions, design variables and restraint functions on optimization design of hovercraft’s propulsion shafting were analyzed. Applying parameterize modeling method of virtual prototype, combining the studying results of sea excitement, and using generalized reduced gradient optimization algorithm, structure optimization research of hovercraft’s propulsion shafting under whipping condition was done.9. A design idea that a kind of experimental equipment of flexible base-shafting propulsion which could simulate complex sea condition and bese excitement could be controlled was put forward first. A kind of simulation experimential facility having flexible base and propulsion shaft ing was designed and built. The experimential facility could supply effective experimental-research means to study dynamic characteristics of hovercraft’s propulsion shafting. Using the experimental facility, experimental research was performed about characteristics of hovercraft’s propulsion shafting. Experimental research showed that the studied method that been presented in the dissertation about hovercraft’s propulsion shafting was effective and correct.Finally, main originalities of the dissertation were summarized, and some future directions of research were presented by author.更多还原