Numerical study on the vibration characteristics of automobile brake disk and pad

Author(s):  
Xianjie Meng ◽  
Guangqiang Wu ◽  
Lin He
1996 ◽  
Vol 3 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Sandor Stephen Mester ◽  
Haym Benaroya

Extensive work has been done on the vibration characteristics of perfectly periodic structures. Disorder in the periodic pattern has been found to lead to localization in one-dimensional periodic structures. It is important to understand localization because it causes energy to be concentrated near the disorder and may cause an overestimation of structural damping. A numerical study is conducted to obtain a better understanding of localization. It is found that any mode, even the first, can localize due to the presence of small imperfections.


Author(s):  
Zhifeng Shi ◽  
Jing Liu ◽  
Shaojiang Dong

Roller bearings are key parts in different machineries. As one of the major incipient failure models in the bearings, the surface crack will be enlarged to be a large spalling failure. Moreover, the abrupt changes in the contact characteristics caused by the crack zone would produce unacceptable impulses, which can affect the bearing vibrations. Thus, a study of the contact characteristics and vibrations of the bearings including the surface crack could be conducive for the incipient fault monitoring methods. To overcome this issue, a finite element model is proposed to obtain the influences of the depth and slope angle of a surface crack on the contact characteristics in a roller bearing. The relationships between the contact characteristics (contact deformation, width and stiffness) and crack sizes (depth and slope angle) are established. To study the influences of the surface crack sizes on the bearing vibrations, a dynamic model of the roller bearing considering the surface crack is also proposed. An experiment is introduced to verify the proposed method. It seems that the crack depth and slope angle can greatly affect the contact and vibration characteristics of the bearing. This study provides a helpful numerical approach for understanding the contact and vibration characteristics of roller bearings with various surface cracks.


Author(s):  
Esmatullah Maiwand Sharify ◽  
Norio Arai ◽  
Shun Takahashi

This contribution presents the numerical study of Fluid Structure Interaction (FSI) problems and discusses the oscillatory characteristics of the elastic bodies and flowfield around circular cylinders. This paper deals with the motion of the elastic body and the flowfield using computational fluid dynamics (CFD) in two-dimensional and three-dimensional simulations. The governing equations are the continuity equation and incompressible Navier-Stokes equations. These equations are solved by MAC (Marker and cell) method by using Poisson equation for pressure component and momentum equations for velocity components. The convective terms of momentum equations are discretized by the third-order upwind Kawamura-Kuwahara scheme. All of the discretized equations are solved by the Successive over-relaxation (SOR) method. The equation of motion consists of mass-spring-damper system and it is solved by the 4th order Runge-Kutta method. The objective is to investigate the influence of the elastic surfaces with respect to the vibration characteristics of cylinders in unsteady flows. As a result, it is obtained that due to passive deformation of elastic surface for single cylinder the drag coefficient increases in both 2D and 3D cases. It is noticed that the effect of elastic surface in 2D case is stronger compared to 3D case. In the case of double cylinders, the elastic surface affects on vibration characteristics of upstream and downstream cylinders, and it is significant on downstream cylinder.


2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Deshui Xu ◽  
Jingtao Du ◽  
Chuan Tian

In this paper, flexural vibration and power flow transmission of a ship propulsion shafting structure are analyzed via energy principle description in conjunction with Rayleigh–Ritz procedure, in which the shafting vibration displacement is constructed as a superposition of Fourier series and boundary-smoothing supplementary functions. Effect of the distributed bearing support and thrust loading of propulsion shafting system is considered in terms of potential energy of system Lagrangian. Numerical examples are presented to demonstrate the reliability and effectiveness of the established model by comparing results with those from finite element method. Results show that the current model can deal with the vibration analysis of ship propulsion shafting with thrust loading and distributed bearing very well. Influence of boundary restraints, stiffness of distributed bearings, and thrust loading on vibration characteristics of ship shafting system is studied and addressed. Numerical study on power flow analysis is also conducted to investigate the characteristics of vibrational energy transmission in such practical structure. Results show that the stiffness of spatial bearing support has significant influence on vibrational energy transmission and thrust force will greatly affect the total input power into such structure.


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