【作者】 王新波；

【导师】 王德伦；

【作者基本信息】 大连理工大学 ， 机械设计及理论， 2010， 硕士

【摘要】 风电制动器是风力发电机上的关键部件,当前我国的风电制动器主要依靠进口,市场份额被国外品牌控制。制动器的制动过程是一个涉及到多物理场的复杂过程。研究风电制动器的制动过程,不仅可以更好的了解制动器的摩擦制动机理,而且对打破国外垄断、发展自主民族品牌的制动器也具有重大的意义。本文以液压厂的SVENDBORG制动器为研究对象,结合热-结构耦合的理论基础,建立了制动器的热-结构的数值模型,并通过该模型分别模拟了制动盘和制动衬片的温度场和应力场,模拟结果揭示了制动盘和制动衬片制动过程中温度、等效应力、温度梯度等的变化及分布规律。首先,本文介绍了热-结构耦合的基本理论,包括热传导方程的建立、瞬态温度场的有限元法、热应力的有限元计算以及热-结构耦合方法。然后,建立了制动器温度场的数值模型。根据制动器的工作状况,提出了温度场模型的假设条件。依据制动器的实际结构,在ANSYS软件中,建立了制动盘和制动衬片的几何模型,并根据实际工况确定了模型的初始条件和边界条件。在计算了制动盘的热载荷之后,还确定了各个物理性能参数、运动参数以及热性能参数。接着,根据前面的温度场的数字模型,用ANSYS有限元软件数值模拟了制动盘和制动衬片的温度场。针对制动器紧急制动时制动盘的旋转运动规律,本文提出了循环迭代的计算方法,用来进行热流密度的加载。模拟结果表明：制动盘的摩擦区域上点的温度分布是从不均匀到均匀,再从均匀到不均匀变化的；而制动衬片的摩擦区域的点的温度的分布在径向方向上呈明显的轮廓线分布。最后,模拟了制动器的应力场。针对ANSYS一般单元不能实现大转动位移,本文采用184单元刚性梁特性来带动制动盘转动,从而来模拟制动盘的减速运动。在充分考虑温度场和应力场的耦合关系的情况下,本文提出了分步加载的方法来计算制动盘和制动衬片的应力场。应力场的模拟反映：制动盘制动摩擦区域的点的等效应力分布与其温度场的分布基本一致,而制动衬片的应力场分布不同于其温度场分布。本文的分析方法对模拟制动器的摩擦制动工况具有参考价值。计算分析结果为进一步深刻分析摩擦制动器的温度场和应力场的相互耦合关系、研制高性能的风电制动器提供了基础。更多还原

【Abstract】 The brake is a key part of wind-turbine generation. Nowadays the brake of wind-turbine generation in China relies mainly on imports and the domestic market shares are controlled by foreign brands. The braking is a complicated process involving multi-physics. The research on the braking process not only can better understand frictional mechanism of the brake, but also have significant impact on breaking the foreign monopoly and develop independent innovation brand.Based on SVENDBORG brake of hydraulic factory and combined with theoretical foundation of thermal-structure coupling, the paper establishes the numerical model for the brake and simulates this model and simulates the temperature field and stress field of the disc and pad according to this model. The results reveal the regularity of difference and distribution of the temperature and Von Mises stress and temperature gradient for the disc and pad during the braking.Firstly, the paper introduces the basic theory of thermal-structural coupling. It includes the establishment of temperature field for the brake, the finite element method of transient temperature field, the finite element calculation of thermal stress and the introduction of the method of thermal-structure coupling.Secondly, the numerical model of the temperature for the brake is established. According to the working condition of the brake, the hypothetical condition of the temperature field for the brake is proposed. In accordance with actual structure of the brake, the thesis establishes the geometrical model of disc and pad in ANSYS software and confirms the initial conditions and boundary conditions of the model on the basis of actual condition. After calculating the thermal loading of disc, the paper confirms physical performance parameters, motional parameters and thermal parameters.Furthermore, based on the numerical model of previous temperature field, the paper simulates the temperature field with ANSYS finite element analysis software. According to the rotating motion of disc when emergently braking, the thesis comes up with a method of iterative calculation to load the heat flux. The results reveal that the temperature distribution of points in the frictional region of the disc is from non-uniform to uniform and later from evenly to non-uniform while the distribution of the counterpart in pad has obvious contour lines in radial direction. Finally, the stress field of the brake is simulated. Since the general unit cannot achieve large rotation in ANSYS, in order to simulate the deceleration movement of the disc, this paper adopts 184 Element to drive the brake. Under the consideration of the mutual coupling relationship for the temperature field and stress field, it puts forward a method of step-by-step loading to calculate the stress field of the disc and the pad. The conclusion shows that the Von Mises stress distribution and the temperature distribution of disc is basically the same while that of pad are different.The analytical method in the paper could supply reference for later researchers on the simulating of frictional braking process and the calculation results provide a basis for further analyzing the mutual coupling relationship of the temperature field and stress field and developing high-performance wind-power brake.更多还原