Development of an Insertion Loss for Vibration Isolation of Building Services Equipment

2003 ◽  
Vol 46 (2) ◽  
pp. 193-205 ◽  
Author(s):  
C. M. Mak ◽  
George K.C. Or
Keyword(s):  
Insertion Loss ◽  
Vibration Isolation

Research on Evaluation of Vibration Isolation Efficiency Based on Power Flow Analysis

2014 ◽  
Vol 590 ◽  
pp. 149-154 ◽  
Author(s):  
Xue Tao Weng ◽  
Rui Huo ◽  
Shu Ying Li ◽  
Cui Ping Liu
Keyword(s):  
Insertion Loss ◽  
Power Flow ◽  
Vibration Isolation ◽  
Flow Analysis ◽  
Vibration Level ◽  
Transmitted Power ◽  
Research On Evaluation ◽  
Power Flow Analysis ◽  
Level Difference ◽  
Set Up

Problems of estimation of vibration isolation effectiveness are discussed based on vibratory power flow analysis, and a new insertion loss character — power flow insertion loss is proposed for evaluation of isolation efficiency. Spectra characteristics of the power flow insertion loss and their relationship with transmitted power flow and vibration level difference are investigated through numerical simulation. And in consideration of the inconvenience of practical testing of insertion loss and power flow, an attempt is made to set up numerical correspondence between power flow insertion loss and the current widely applied vibration level difference measurement, through theoretical analysis and experiments.

scholarly journals Evaluation Method of the Vibration Reduction Effect Considering the Real Load- and Frequency-Dependent Stiffness of Slab-Track Mats

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 452
Author(s):  
Zeming Zhao ◽  
Kai Wei ◽  
Wenhao Ding ◽  
Fang Cheng ◽  
Ping Wang
Keyword(s):  
Frequency Dependence ◽  
Insertion Loss ◽  
Vibration Isolation ◽  
Evaluation Method ◽  
Vibration Reduction ◽  
Frequency Dependent ◽  
Tangent Stiffness ◽  
Slab Track ◽  
Secant Stiffness ◽  
Reduction Effect

The purpose of this research was to investigate and improve the accuracy of the existing slab-track mat (STM) specifications in the evaluation of the vibration reduction effect. The static nonlinearity and dynamic mechanical characteristics of three types of STMs were tested, and then a modified fractional derivative Poynting–Thomson (FDPT) model was used to characterize the preload and frequency dependence. A modified vehicle–floating slab track (FST) coupled dynamic model was established to analyze the actual insertion loss. The insertion loss error evaluated by the frequency-dependent tangent stiffness increased with the increase in STM nonlinearity, and the error obtained by the third preload tangent stiffness was usually greater than that of the second preload. Compared with the secant stiffness, the second preload frequency-dependent tangent stiffness was more suitable for evaluating STMs with high-static–low-dynamics (HSLD) stiffness. In order to reflect the frequency dependence effect and facilitate engineering applications, it is recommended that second preload tangent stiffness corresponding to the natural frequency of the FST be used for evaluation. Furthermore, the insertion loss of the STMs with monotonically increased stiffness decreased as the axle load increased, and the opposite was true for the STMs with monotonically decreased stiffness. The vibration isolation efficiency of the STMs with HSLD stiffness was both stable and better than that of the STMs with monotonic stiffness.

Comparison of TEM and STM observations of small silver clusters on different carbon supports

1990 ◽  
Vol 48 (4) ◽  
pp. 264-265
Author(s):  
Bernd Tesche ◽  
Tobias Schilling
Keyword(s):  
Vibration Isolation ◽  
Pyrolytic Graphite ◽  
Carbon Film ◽  
Silver Clusters ◽  
Carbon Supports ◽  
Stacking Order ◽  
System P ◽  
High Resolution Tem ◽  
High Degree ◽  
Degree Of Order

The objective of our work is to determine:a) whether both of the imaging methods (TEM, STM) yield comparable data andb) which method is better suited for a reliable structure analysis of microclusters smaller than 1.5 nm, where a deviation of the bulk structure is expected.The silver was evaporated in a bell-jar system (p 10−5 pa) and deposited onto a 6 nm thick amorphous carbon film and a freshly cleaved highly oriented pyrolytic graphite (HOPG).The average deposited Ag thickness is 0.1 nm, controlled by a quartz crystal microbalance at a deposition rate of 0.02 nm/sec. The high resolution TEM investigations (100 kV) were executed by a hollow-cone illumination (HCI). For the STM investigations a commercial STM was used. With special vibration isolation we achieved a resolution of 0.06 nm (inserted diffraction image in Fig. 1c). The carbon film shows the remarkable reduction in noise by using HCI (Fig. 1a). The HOPG substrate (Fig. 1b), cleaved in sheets thinner than 30 nm for the TEM investigations, shows the typical arrangement of a nearly perfect stacking order and varying degrees of rotational disorder (i.e. artificial single crystals). The STM image (Fig. 1c) demonstrates the high degree of order in HOPG with atomic resolution.

Vibration isolation of power tool operators

1983 ◽  
Author(s):  
C. W. Suggs ◽  
C. F. Abrams
Keyword(s):  
Vibration Isolation

An hourglass-type electromagnetic isolator with negative resistance electromagnetic shunt circuit

2020 ◽  
Vol 64 (1-4) ◽  
pp. 549-556
Author(s):  
Yajun Luo ◽  
Linwei Ji ◽  
Yahong Zhang ◽  
Minglong Xu ◽  
Xinong Zhang
Keyword(s):  
Vibration Isolation ◽  
Electromechanical Coupling ◽  
Coupling Effect ◽  
Negative Resistance ◽  
Isolation System ◽  
Amplitude Vibration ◽  
Vibration Responses ◽  
The Stability ◽  
Isolation Performance ◽  
Shunt Circuit

The present work proposed an hourglass-type electromagnetic isolator with negative resistance (NR) shunt circuit to achieve the effective suppression of the micro-amplitude vibration response in various advanced instruments and equipment. By innovatively design of combining the displacement amplifier and the NR electromagnetic shunt circuit, the current new type of vibration isolator not only can effectively solve the problem of micro-amplitude vibration control, but also has significant electromechanical coupling effect, to obtain excellent vibration isolation performance. The design of the isolator and motion relationship is presented firstly. The electromechanical coupling dynamic model of the isolator is also given. Moreover, the optimal design of the NR electromagnetic shunt circuit and the stability analysis of the vibration isolation system are carried out. Finally, the simulation results about the transfer function and vibration responses demonstrated that the isolator has a significant isolation performance.

Method for Evaluating Insertion Loss of EMI Filter Connected to Semiconductor Power Converters

2012 ◽  
Vol 132 (7) ◽  
pp. 727-735 ◽  
Author(s):  
Michio Tamate ◽  
Tamiko Sasaki ◽  
Akio Toba ◽  
Yasushi Matsumoto ◽  
Keiji Wada ◽  
...  
Keyword(s):  
Insertion Loss ◽  
Power Converters ◽  
Emi Filter

Performance and Reliability of a MEMS-based tunable optical filter operating in the 1565 nm-1525 nm wavelength range

2002 ◽  
Vol 722 ◽  
Author(s):  
T. S. Sriram ◽  
B. Strauss ◽  
S. Pappas ◽  
A. Baliga ◽  
A. Jean ◽  
...  
Keyword(s):  
Silicon Nitride ◽  
Line Width ◽  
Insertion Loss ◽  
Optical Filter ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Reliability Testing ◽  
Silicon Nitride Membrane ◽  
Tunable Optical Filter ◽  
Extensive Performance

AbstractThis paper describes the results of extensive performance and reliability characterization of a silicon-based surface micro-machined tunable optical filter. The device comprises a high-finesse Fabry-Perot etalon with one flat and one curved dielectric mirror. The curved mirror is mounted on an electrostatically actuated silicon nitride membrane tethered to the substrate using silicon nitride posts. A voltage applied to the membrane allows the device to be tuned by adjusting the length of the cavity. The device is coupled optically to an input and an output single mode fiber inside a hermetic package. Extensive performance characterization (over operating temperature range) was performed on the packaged device. Parameters characterized included tuning characteristics, insertion loss, filter line-width and side mode suppression ratio. Reliability testing was performed by subjecting the MEMS structure to a very large number of actuations at an elevated temperature both inside the package and on a test board. The MEMS structure was found to be extremely robust, running trillions of actuations without failures. Package level reliability testing conforming to Telcordia standards indicated that key device parameters including insertion loss, filter line-width and tuning characteristics did not change measurably over the duration of the test.

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