meifal rusli - Academia.edu (original) (raw)
Papers by meifal rusli
Structural Engineering and Mechanics, 2016
Dynamics Design Conference, Aug 22, 2005
Advanced Materials Research, 2012
International Journal of Structural Stability and Dynamics, 2014
In recent research it was found that squeal noise caused by friction-induced vibration can result... more In recent research it was found that squeal noise caused by friction-induced vibration can result in mode coupling instability. Presently, there is no method that can be reliably used to eliminate this kind of noise. This paper is focused on the use of dynamic vibration absorbers (DVAs) to suppress the generation of squeal noise. The performance of the DVA is investigated numerically for two simple cases, i.e. a simple two-degree of freedom model, and an L-shape space frame. It is found that the DVA can be applied to shifting or reducing the unstable region of mode coupling, by which the unstable region is removed from the operating condition. Particularly, the addition of the DVA in horizontal direction on the near-point-of-friction can possibly avoid unstable mode coupling. However, the addition in vertical direction will increase the possibility of squeal noise incident. Moreover, a high frequency DVA in horizontal direction at the near-point-of-friction shifts the unstable region into higher normal contact sti®ness and higher friction coe±cient. Consequently, addition of a mass with very sti® spring or a rigid mass in the horizontal direction can prevent the occurrence of unstable mode coupling, as long as it is not coupled with the vertical direction. If the added mass a®ects the dynamic behaviors in both vertical and horizontal directions, squeal noise in the original normal contact sti®ness can still occur.
JSME International Journal Series C, 2006
Journal of System Design and Dynamics, 2008
Friction between two relatively sliding surfaces in mechanical structures possibly excites unstab... more Friction between two relatively sliding surfaces in mechanical structures possibly excites unstable vibration, which emits squeal noise. In this paper, the authors propose an idea to predict the possibility of squeal noise occurrence in actual structures having relative sliding surfaces with friction by means of experimental modal analysis and experimental spatial matrix identification. Using spatial matrices that derived from experimental modal data, unstable mode coupling that causes squeal noise can be predicted. By this method it is possible to calculate the possibility of squeal noise incident and its frequency within the practical realistic range of friction coefficient and contact stiffness. The method is presented with showing an experimental verification study using a simple L shape frame.
Journal of Sound and Vibration, 2007
Dry contact sliding between two structures is frequently found to generate squeal noise in certai... more Dry contact sliding between two structures is frequently found to generate squeal noise in certain topography condition of contact surface. Furthermore, a different surface topography may generate squeal noise at different frequencies. In this paper, authors investigate the effect of topography of contact surfaces to the normal contact stiffness, the tangential contact stiffness, and the friction coefficient. The normal and tangential contact stiffness are determined by a classical model of asperity on contact surface. These parameters will be the dominant factors of the squeal noise generation by means of mode-coupling analysis. Numerical simulation-based investigation is carried out using two simple models, i.e. a two-degree of freedom model and a simple space frame model. The simulation results show that a structure has only one or few pairs of couple modes with complex eigenvalues at certain contact conditions. For a system with multi-degrees of freedom, some mode shapes make couples in different contact conditions. On the other hand, smoother contact surfaces have higher normal and tangential contact stiffness. Furthermore, higher tangential contact stiffness and higher coefficient of friction will increase the possibility of squeal generation. Hence, it is understandable why the squeal noise appears and vanishes in some surface topography and has different frequencies at different values of surface roughness. r
A Combination of dynamic vibration absorbers (DVAs) consist of Tuned Mass Damper (TMD) and Tuned ... more A Combination of dynamic vibration absorbers (DVAs) consist of Tuned Mass Damper
(TMD) and Tuned Liquid Column Damper (TLCD) for reducing vibration response of a two-DOF shear structure model is proposed. The absorber parameters are optimized using Genetic Algorithm (GA). The cost function is derived from the ratio between structure response and the excitation signal. The limitation in absorber space and fluid motion are considered during optimization process. The simulation results show that GA optimization procedure is effective to get the optimal absorber parameters in the case of limited absorber size and motion
Structural Engineering and Mechanics, 2016
Dynamics Design Conference, Aug 22, 2005
Advanced Materials Research, 2012
International Journal of Structural Stability and Dynamics, 2014
In recent research it was found that squeal noise caused by friction-induced vibration can result... more In recent research it was found that squeal noise caused by friction-induced vibration can result in mode coupling instability. Presently, there is no method that can be reliably used to eliminate this kind of noise. This paper is focused on the use of dynamic vibration absorbers (DVAs) to suppress the generation of squeal noise. The performance of the DVA is investigated numerically for two simple cases, i.e. a simple two-degree of freedom model, and an L-shape space frame. It is found that the DVA can be applied to shifting or reducing the unstable region of mode coupling, by which the unstable region is removed from the operating condition. Particularly, the addition of the DVA in horizontal direction on the near-point-of-friction can possibly avoid unstable mode coupling. However, the addition in vertical direction will increase the possibility of squeal noise incident. Moreover, a high frequency DVA in horizontal direction at the near-point-of-friction shifts the unstable region into higher normal contact sti®ness and higher friction coe±cient. Consequently, addition of a mass with very sti® spring or a rigid mass in the horizontal direction can prevent the occurrence of unstable mode coupling, as long as it is not coupled with the vertical direction. If the added mass a®ects the dynamic behaviors in both vertical and horizontal directions, squeal noise in the original normal contact sti®ness can still occur.
JSME International Journal Series C, 2006
Journal of System Design and Dynamics, 2008
Friction between two relatively sliding surfaces in mechanical structures possibly excites unstab... more Friction between two relatively sliding surfaces in mechanical structures possibly excites unstable vibration, which emits squeal noise. In this paper, the authors propose an idea to predict the possibility of squeal noise occurrence in actual structures having relative sliding surfaces with friction by means of experimental modal analysis and experimental spatial matrix identification. Using spatial matrices that derived from experimental modal data, unstable mode coupling that causes squeal noise can be predicted. By this method it is possible to calculate the possibility of squeal noise incident and its frequency within the practical realistic range of friction coefficient and contact stiffness. The method is presented with showing an experimental verification study using a simple L shape frame.
Journal of Sound and Vibration, 2007
Dry contact sliding between two structures is frequently found to generate squeal noise in certai... more Dry contact sliding between two structures is frequently found to generate squeal noise in certain topography condition of contact surface. Furthermore, a different surface topography may generate squeal noise at different frequencies. In this paper, authors investigate the effect of topography of contact surfaces to the normal contact stiffness, the tangential contact stiffness, and the friction coefficient. The normal and tangential contact stiffness are determined by a classical model of asperity on contact surface. These parameters will be the dominant factors of the squeal noise generation by means of mode-coupling analysis. Numerical simulation-based investigation is carried out using two simple models, i.e. a two-degree of freedom model and a simple space frame model. The simulation results show that a structure has only one or few pairs of couple modes with complex eigenvalues at certain contact conditions. For a system with multi-degrees of freedom, some mode shapes make couples in different contact conditions. On the other hand, smoother contact surfaces have higher normal and tangential contact stiffness. Furthermore, higher tangential contact stiffness and higher coefficient of friction will increase the possibility of squeal generation. Hence, it is understandable why the squeal noise appears and vanishes in some surface topography and has different frequencies at different values of surface roughness. r
A Combination of dynamic vibration absorbers (DVAs) consist of Tuned Mass Damper (TMD) and Tuned ... more A Combination of dynamic vibration absorbers (DVAs) consist of Tuned Mass Damper
(TMD) and Tuned Liquid Column Damper (TLCD) for reducing vibration response of a two-DOF shear structure model is proposed. The absorber parameters are optimized using Genetic Algorithm (GA). The cost function is derived from the ratio between structure response and the excitation signal. The limitation in absorber space and fluid motion are considered during optimization process. The simulation results show that GA optimization procedure is effective to get the optimal absorber parameters in the case of limited absorber size and motion