船用齿轮箱动态激励模拟及动力学性能优化

发布时间：2018-01-02 07:38

本文关键词：船用齿轮箱动态激励模拟及动力学性能优化　出处：《重庆大学》2015年硕士论文　论文类型：学位论文

【摘要】：船用齿轮箱作为船舶推进系统的关键部件,其性能好坏直接决定了船舶的运行可靠性。随着船舶装备制造技术的进步,船用齿轮箱正朝着高转速、大功率、高精度、轻量化、低噪声等方向发展,开展齿轮箱动态激励模拟及动力学性能优化研究,对船用齿轮箱减振降噪具有十分重要的理论意义和应用前景。论文依托于国家自然科学基金项目,以船用齿轮箱为研究对象,进行啮合性能分析、动态激励模拟、振动特性仿真、传动系统离散优化、模态-响应联合优化。论文主要的研究工作如下:①基于Romax软件,综合考虑轴的弯曲和扭转变形、轴承的弹性位移以及轮齿的制造和装配误差,建立船用齿轮箱传动系统静力学模型,分析了各齿轮副的载荷分布和轴承的支撑刚度,并对由齿轮时变啮合刚度、传动误差和啮合冲击引起的内部激励以及由柴油机扭矩波动引起的外部激励进行了模拟。②在ANSYS软件中,构建了船用齿轮箱多体耦合动力有限元模型,采用分块Lanczos法进行模态分析,得出齿轮箱的固有频率及振型;采用模态叠加法对齿轮系统进行振动响应分析,得到了箱体表面各评价点的振动位移、振动速度和振动加速度。③借助ANSYS软件,以避开系统特征频率或减小振动加速度为优化目标,箱体和轴系尺寸参数为设计变量,齿轮箱体积、箱体等效应力和综合位移为约束条件,建立了船用齿轮箱单目标动力优化有限元模型,运用梯度法对各设计变量进行灵敏度分析,采用先零阶后一阶的优化方法分别对船用齿轮箱进行模态和响应优化。④为实现模态和响应最优设计变量的一致性,以避开系统特征频率和减小振动加速度为优化目标,基于多目标优化理论,将振动模态和动态响应两个子目标函数线性加权组合成单目标函数,建立了船用齿轮箱模态-响应联合优化有限元模型,通过灵敏度分析确定优化设计变量,进而对齿轮箱进行动力学性能优化。⑤基于集中参数法建立了齿轮箱传动系统纯扭转动力学模型,采用谐波平衡法求解系统动力学微分方程,得到传动系统各构件振动响应解析解,进而构造包含所有构件质量和振动加速度的目标函数,以齿数、模数及螺旋角等为设计变量,轮齿强度、传动比、重合度等为约束条件,建立传动系统动力优化模型,采用分支定界算法,编写混合离散非线性优化程序,求得传动系统最优设计变量。
[Abstract]:As the key component of marine propulsion system, the performance of marine gearbox directly determines the operational reliability of ship. With the development of ship equipment manufacturing technology, marine gearbox is moving towards high speed and high power. With the development of high precision, light weight and low noise, the dynamic excitation simulation and dynamic performance optimization of the gearbox are carried out. It has very important theoretical significance and application prospect to reduce vibration and noise of marine gearbox. Based on the project of National Natural Science Foundation, this paper analyzes the meshing performance of marine gearbox. Dynamic excitation simulation, vibration simulation, discrete optimization of transmission system, modal response joint optimization. The main research work of this paper is as follows: 1 based on Romax software, considering the bending and torsional deformation of shaft synthetically. Based on the elastic displacement of bearing and the manufacturing and assembly error of gear tooth, the static model of marine gearbox transmission system is established, the load distribution of each gear pair and the bearing supporting stiffness are analyzed, and the time-varying meshing stiffness of the gear is analyzed. The internal excitation caused by transmission error and meshing impact and the external excitation caused by torque fluctuation of diesel engine were simulated. 2. In ANSYS software, the multi-body coupling dynamic finite element model of marine gearbox was constructed. The modal analysis is carried out by block Lanczos method, and the natural frequency and mode shape of the gearbox are obtained. The vibration response of gear system is analyzed by modal superposition method, and the vibration displacement, vibration velocity and vibration acceleration of each evaluation point on the surface of the box are obtained by ANSYS software. The optimization objective is to avoid the characteristic frequency of the system or to reduce the vibration acceleration, the dimension parameters of the box and shafting are the design variables, the volume of the gear box, the equivalent stress of the box and the comprehensive displacement are the constraint conditions. The finite element model of ship gearbox single objective dynamic optimization is established, and the sensitivity of each design variable is analyzed by gradient method. The modal and response optimization of the ship gearbox is carried out by the first zero order and then the first order optimization method respectively. 4 is the consistency of the modal and response optimal design variables. In order to avoid the characteristic frequency of the system and reduce the vibration acceleration as the optimization objective, based on the multi-objective optimization theory, the vibration mode and the dynamic response of the two sub-objective functions are linearly weighted into a single-objective function. The modal response optimization finite element model of ship gearbox is established, and the optimal design variables are determined by sensitivity analysis. Based on the lumped parameter method, the pure torsion dynamic model of the gearbox transmission system is established, and the harmonic balance method is used to solve the dynamic differential equation of the system. The analytical solution of the vibration response of each component of the transmission system is obtained, and then the objective function including the mass and the vibration acceleration of all the components is constructed. The tooth number, modulus and spiral angle are taken as the design variables, the gear tooth strength and the transmission ratio are taken as the design variables. The dynamic optimization model of transmission system is established under the constraint condition of coincidence degree. The hybrid discrete nonlinear optimization program is compiled by using branch and bound algorithm to obtain the optimal design variables of transmission system.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U664.3

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