• 전기학회논문지
• /
• 제59권8호
• /
• pp.1482-1488
• /
• 2010

Recently to increase the productivity and improve the quality in the industrial process, suppressing the residual vibration in motion control systems becomes the essential problem to solve. One of the methods to suppress the residual vibration is the input shaping technique. It is based on parameters of the system model; however, the parameters are usually difficult to obtain. This paper shows the effects of the residual vibration caused by the variation of the general velocity profile for the system with two vibration modes, and also shows the effects of the input shaping filter based on the parameters of system model. Finally, the simulation results show that the proposed input shaping filter using an artificial immune algorithm is more effective for suppressing residual vibrations than genetic algorithm.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 1994년도 봄 학술발표회 논문집
• /
• pp.89-94
• /
• 1994

Latticed domes take form a curved surface by arranged members with certain patterns. For this reason, it is possible for the characteristics of vibration to complicate by change of various parameters of dome; grid-pattern, boundary condition and ratio of radius-height etc. Therefore, it is important to clarify the effect by these parameters before generalized dynamic response analysis. So this study deals with free vibration analysis of latticed domes and makes clear an effect of shape coefficient, that is, geometrical characteristics of latticed domes, on the vibration characteristics.

• Steel and Composite Structures
• /
• 제11권5호
• /
• pp.403-421
• /
• 2011

In the present manuscript, geometrically nonlinear free vibration analysis of thin laminated plates resting on non-linear elastic foundations is investigated. Winkler-Pasternak type foundation model is used. Governing equations of motions are obtained using the von Karman type nonlinear theory. The method of discrete singular convolution is used to obtain the discretised equations of motion of plates. The effects of plate geometry, boundary conditions, material properties and foundation parameters on nonlinear vibration behavior of plates are presented.

• Smart Structures and Systems
• /
• 제17권6호
• /
• pp.1107-1127
• /
• 2016

Studies on dynamic characteristics of the hanger vibration using field monitoring data are important for the design and evaluation of high-speed railway truss arch bridges. This paper presents an analysis of the hanger's dynamic displacement responses based on field monitoring of Dashengguan Yangtze River Bridge, which is a high-speed railway truss arch bridge with the longest span throughout the world. The three vibration parameters, i.e., dynamic displacement amplitude, dynamic load factor and vibration amplitude, are selected to investigate the hanger's vibration characteristics in each railway load case including the probability statistical characteristics and coupled vibration characteristics. The influences of carriageway and carriage number on the hanger's vibration characteristics are further investigated. The results indicate that: (1) All the eight railway load cases can be successfully identified according to the relationship of responses from strain sensors and accelerometers in the structural health monitoring system. (2) The hanger's three vibration parameters in each load case in the longitudinal and transverse directions have obvious probabilistic characteristics. However, they fall into different distribution functions. (3) There is good correlation between the hanger's longitudinal/transverse dynamic displacement and the main girder's transverse dynamic displacement in each load case, and their relationships are shown in the hysteresis curves. (4) Influences of the carriageway and carriage number on the hanger's three parameters are different in both longitudinal and transverse directions; while the influence on any of the three parameters presents an obvious statistical trend. The present paper lays a good foundation for the further analysis of train-induced hanger vibration and control.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2003년도 추계학술대회논문집
• /
• pp.946-969
• /
• 2003

Vibration analysis for a coupled MEMS gyroscope design is presented in this paper. MEMS gyroscopes have shown that slight mistuning in fabricated process often leads to significant difference of vibration characteristics between expected and real designs. The difference frequently affects the MEMS gyroscope design in a negative way. As long as the coupling between excited and sensed motions exists, such difference occurs inevitably. In this paper, dimensionless parameters that govern the vibration characteristics of coupled MEMS gyroscope are identified and the effects of the parameters on the vibration characteristics are investigated for the design of the MEMS gyroscope.

• 한국생산제조학회지
• /
• 제7권3호
• /
• pp.29-36
• /
• 1998

In recent year, as the demand about low vibration and noise vehicle is increased constantly. automobile companies try to a lot of things to achieve this demand. Gear rattle vibration become an emergency problem to be cured at idling. There are two kinds method to reduce idle gear rattle vibration One is optimization of clutch damper design parameters(stiffness, hysteresis torque, preload, length of lst stage) the other is system parameters modification(inertia, drag torque, backlash, etc) But these methods are impossible to estimate influence rate of each gearpair on the idle gear rattle vibration. In this study, 14degrees of freedom nonlinear model is developed to analyze influnce rate of each gearpair on the idle gear rattle vibration and the counterplan to reduce the gear noise is suggeted through the shift system modification.

• 한국소음진동공학회논문집
• /
• 제14권8호
• /
• pp.655-660
• /
• 2004

Vibration analysis for a coupled MEMS gyroscope design is presented in this paper. Slight mistuning in fabricated MEMS gyroscopes often leads to significant difference of vibration characteristics between expected and real designs. This difference frequently results in a negative effect to the MEMS gyroscope performance. As long as the coupling between excited and sensed motions exists, such difference inevitably occurs. In this paper, dimensionless parameters that govern the vibration characteristics of coupled MEMS gyroscope are identified and the effects of the parameters on the vibration characteristics are investigated.

• 반도체디스플레이기술학회지
• /
• 제2권1호
• /
• pp.15-19
• /
• 2003

Spin etcher can process frontside and backside on the wafer, which is used for etching, stripping, cleaning and wafer reclamation. A new generation of spin etchers has been designed to meet 300mm wafer processing. The larger header and higher spin speed make vibration problem a severe problem in developing equipments. This study shows schematic process of solving practical vibration problems, where it is required to analyze the principal ca uses of vibration problem and find out the method of vibration reduction in spin etcher. The vibration under normal operation is measured in time domain and is analyzed in frequency domain. And modal parameters are obtained through modal test. Using the modal parameters from experiments, the model of finite element method is formulated. From diagnosis using many measurements and analyses, it can be shown that main cause of vibration is unbalance of head.

• Steel and Composite Structures
• /
• 제30권6호
• /
• pp.577-589
• /
• 2019

In this study, on-site testing was carried out to investigate the vibration performance of a composite steel-bar truss slab with steel girder system. Ambient vibration was performed to capture the primary vibration parameters (natural frequencies, damping ratios, and mode shapes). The composite floor possesses low frequency (< 10 Hz) and damping (< 2%). Based on experimental, theoretical, and numerical analyses on natural frequencies and mode shapes, the boundary condition of SCSC (i.e., two opposite edges simply-supported and the other two edges clamped) is deemed more reasonable for the composite floor. Walking excitations by one person (single excitation), two persons (dual excitation), and three persons (triple excitation) were considered to evaluate the vibration serviceability of the composite floor. The measured acceleration results show a satisfactory vibration perceptibility. For design convenience and safety, a crest factor ${\beta}_{rp}$ describing the ratio of peak acceleration to root-mean-square acceleration induced from the walking excitations is proposed. The comparisons of the modal parameters determined by ambient vibration and walking tests reveal the interaction effect between the human excitation and the composite floor.

• 한국철도학회논문집
• /
• 제16권5호
• /
• pp.358-364
• /
• 2013

전편에서 제시되었던 진동소음 데이터를 기초로 하여 철도차량기지 주변에 기 건설되어 있던 고층아파트 단지의 진동소음 방지대책 수립에 필요한 쟁점들을 검토하고 설계단계에서 필요한 방진기법을 논하였다. 특히, 차량운행속도, 인공대지의 물리적 특징, 건축물 지지구조의 물성치, 아파트 층별구조의 동특성 등에 대하여 진동측면에서 논의하였다. 논문에서 제안된 설계변수와 사례는 향후 개발 예상되는 철도 주변 부지 건축물의 환경문제를 최소화하는 가이드라인으로 사용될 수 있다. 특히, 주민이 거주하는 건축물에 대해서는 설계단계에서부터 합리적인 소음진동 방지대책의 적용이 요구되며, 적극적인 대책을 수립하면 사회적인 비용 또한 저감될 수 있을 것으로 판단된다.