Simulation analysis and experimental study on high frequency friction noise of vehicle V-ribbed belts

In order to improve the service life of the V-ribbed belt and the ride comfort of the vehicle, the friction noise of V-ribbed belt was studied by simulation and experiment. A theoretical model of V-ribbed belts vibration is established, and the conditions for unstable vibration are derived. Based on the theory of mode coupling, the causes of high frequency friction noise of V-ribbed belts are analyzed, and it is considered that the coupling between the vibration of the V-ribbed belts and the natural frequency of the belts’ cross section causes the self-excited vibration of the belt, resulting in high frequency friction noise. Firstly, ANSYS Workbench is used to identify the belts’ cross sections with 3, 4, and 6 wedges, and the natural frequencies of the belts’ cross sections are obtained. Then on the belt drive friction tester, the influences of tension and relative sliding speed on the frequency of high frequency friction noise is studied using a single factor test method, and the frequency response curve of high frequency friction noise is also analyzed. The results of the experiment and simulation show that the transverse vibration of the V-ribbed belts is closely related to the phase and amplitude of the high frequency friction noise, and the changes in tension and relative sliding speed do not affect the frequency of the high frequency friction noise. The frequency of high frequency friction noise has a good consistency with the natural frequency of belts’ cross section, which shows that mode coupling causes the strong self-excited vibration of the V-ribbed belts and the high frequency friction noise. It provides a method and theoretical basis for the control of friction noise.

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Numerical Investigation of the Geometrical Effect on Flow-Induced Vibration Performance of Pivoted Bodies

Energies ◽

10.3390/en14041128 ◽

2021 ◽

Vol 14 (4) ◽

pp. 1128

Author(s):

Hamid Arionfard ◽

Sina Mohammadi

Keyword(s):

Natural Frequency ◽

Cross Section ◽

Cross Sections ◽

Maximum Output Power ◽

Vortex Formation ◽

Circular Cross Section ◽

Maximum Output ◽

Flow Induced Vibration ◽

Geometrical Effect ◽

Geometrical Effects

In this study, the Flow-Induced Vibration (FIV) of pivoted cylinders (at a distance) is numerically investigated as a potential source of energy harvesting. In particular, we investigate the effect of pivot point placement, arm length, and natural frequency on the FIV performance of six different cross sections in the Reynolds number of around 1000. All sections have similar mass, area, and moment of inertia to eliminate non-geometrical effects on the performance. Classical studies show that the synchronization phenomenon (lock-in) occurs when the vortex formation frequency is close enough to the body’s natural frequency. Due to the configuration of the cylinder in this research (pivoted eccentrically), the natural frequency is also a function of the flow velocity as well as the geometrical specifications of the system. The simulation is done for the arm lengths between −3D and +3D for all cross sections. Results show that maximum output power is principally influenced more by the pivot location than the arm length. Although the box cross section has a higher amplitude of vibration, the circular cross section has the highest efficiency followed by the egg shape.

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Bistatic High Frequency Radar Ocean Surface Cross Section for an FMCW Source with an Antenna on a Floating Platform

International Journal of Antennas and Propagation ◽

10.1155/2016/8675964 ◽

2016 ◽

Vol 2016 ◽

pp. 1-9 ◽

Cited By ~ 3

Author(s):

Yue Ma ◽

Weimin Huang ◽

Eric W. Gill

Keyword(s):

Cross Section ◽

Cross Sections ◽

High Frequency ◽

Continuous Wave ◽

Ocean Surface ◽

Radar Cross Section ◽

Second Order ◽

Floating Platform ◽

High Frequency Radar ◽

Radar Cross Sections

The first- and second-order bistatic high frequency radar cross sections of the ocean surface with an antenna on a floating platform are derived for a frequency-modulated continuous wave (FMCW) source. Based on previous work, the derivation begins with the general bistatic electric field in the frequency domain for the case of a floating antenna. Demodulation and range transformation are used to obtain the range information, distinguishing the process from that used for a pulsed radar. After Fourier-transforming the autocorrelation and comparing the result with the radar range equation, the radar cross sections are derived. The new first- and second-order antenna-motion-incorporated bistatic radar cross section models for an FMCW source are simulated and compared with those for a pulsed source. Results show that, for the same radar operating parameters, the first-order radar cross section for the FMCW waveform is a little lower than that for a pulsed source. The second-order radar cross section for the FMCW waveform reduces to that for the pulsed waveform when the scattering patch limit approaches infinity. The effect of platform motion on the radar cross sections for an FMCW waveform is investigated for a variety of sea states and operating frequencies and, in general, is found to be similar to that for a pulsed waveform.

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ASSESSMENT CRITERIA OF OPTIMAL SOLUTIONS FOR CREATION OF RODS WITH PIECEWISE CONSTANT CROSS-SECTIONS WITH STABILITY CONSTRAINTS OR CONSTRAINTS FOR VALUE OF THE FIRST NATURAL FREQUENCY. PART 1: THEORETICAL FOUNDATIONS

International Journal for Computational Civil and Structural Engineering ◽

10.22337/2587-9618-2019-15-4-88-100 ◽

2019 ◽

Vol 15 (4) ◽

pp. 88-100 ◽

Cited By ~ 3

Author(s):

Leonid Lyakhovich ◽

Pavel Akimov ◽

Boris Tukhfatullin

Keyword(s):

Natural Frequency ◽

Cross Section ◽

Cross Sections ◽

Optimization Methods ◽

Optimal Solutions ◽

Continuous Change ◽

Material Consumption ◽

Piecewise Constant ◽

Ideal Object ◽

The Cross

The special properties of optimal systems have been already identified. Besides, criteria has been formulated to assess the proximity of optimal solutions to the minimal material consumption. In particular, the criteria were created for rods with rectangular and I-beam cross-section with stability constraints or constraints for the value of the first natural frequency. These criteria can be used for optimization when the cross sections of a bar change continuously along its length. The resulting optimal solutions can be considered as an idealized object in the sense of the limit. This function of optimal design allows researcher to assess the actual design solution by the criterion of its proximity to the corresponding limit (for example, regarding material consumption). Such optimal project can also be used as a reference point in real design, for example, implementing a step-bystep process of moving away from the ideal object to the real one. At each stage, it is possible to assess the changes in the optimality index of the object in comparison with both the initial and the idealized solution. One of the variants of such a process is replacing the continuous change in the size of the cross sections of the rod along its length with piecewise constant sections. Boundaries of corresponding intervals can be selected based on an ideal feature, and cross-section dimensions can be determined by one of the optimization methods. The distinctive paper is devoted to criteria that allow researcher providing reliable assessment of the endpoint of the optimization process.

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ASSESSMENT CRITERIA OF OPTIMAL SOLUTIONS FOR CREATION OF RODS WITH PIECEWISE CONSTANT CROSS-SECTIONS WITH STABILITY CONSTRAINTS OR CONSTRAINTS FOR VALUE OF THE FIRST NATURAL FREQUENCY. PART 2: NUMERICAL EXAMPLES

International Journal for Computational Civil and Structural Engineering ◽

10.22337/2587-9618-2019-15-4-101-110 ◽

2019 ◽

Vol 15 (4) ◽

pp. 101-110 ◽

Cited By ~ 4

Author(s):

Leonid Lyakhovich ◽

Pavel Akimov ◽

Boris Tukhfatullin

Keyword(s):

Natural Frequency ◽

Cross Section ◽

Cross Sections ◽

Optimal Solutions ◽

Continuous Change ◽

Material Consumption ◽

Piecewise Constant ◽

Numerical Examples ◽

Ideal Object ◽

The Cross

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Dispersion Behaviors of Wedge Waves Propagating Along Wedges with Bilinear Cross Sections

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.321-323.765 ◽

2006 ◽

Vol 321-323 ◽

pp. 765-769

Author(s):

Che Hua Yang ◽

Chun Zen Tsen

Keyword(s):

Finite Element ◽

Cross Section ◽

Cross Sections ◽

Displacement Field ◽

Acoustic Waves ◽

Mode Coupling ◽

Lamb Waves ◽

Apex Angle ◽

Ultrasonic Technique ◽

Wedge Waves

Wedge waves (WW) are guided acoustic waves propagating along the tip of a wedge, with energy tightly confined near the apex. Like Lamb waves, wedge waves with displacement field anti-symmetric about the mid-apex-plane are called anti-symmetric flexural (ASF) modes. This study is focused on exploring the dispersion behaviors of ASF modes propagating along a bilinear wedge (BW). A BW is wedge with a cross section of two apex angles, compared with a linear wedge (LW) having a single apex angle. In the literature, many studies regarding to the dispersion behaviors of ASF modes are reported for LW, but not for BW. In this study, a laser ultrasonic technique and finite element simulations are used to investigate the dispersion behavior of BW-ASF modes. It is found out that a BW-ASF mode is a result of mode coupling between the two LW-ASF modes of the same order corresponding to the two apex angles of the BW.

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Electron Irradiation Effects in Polyoxymethylene Crystals Grown Inside Trioxane Crystals

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010006444x ◽

1971 ◽

Vol 29 ◽

pp. 78-79

Author(s):

J. P. Colson ◽

D. H. Reneker

Keyword(s):

Cross Section ◽

Cross Sections ◽

Detailed Examination ◽

The Other ◽

Electron Micrograph ◽

Irradiation Effects ◽

Threefold Axis ◽

Typical Sample ◽

Polymer Crystals ◽

Chain Axis

Polyoxymethylene (POM) crystals grow inside trioxane crystals which have been irradiated and heated to a temperature slightly below their melting point. Figure 1 shows a low magnification electron micrograph of a group of such POM crystals. Detailed examination at higher magnification showed that three distinct types of POM crystals grew in a typical sample. The three types of POM crystals were distinguished by the direction that the polymer chain axis in each crystal made with respect to the threefold axis of the trioxane crystal. These polyoxymethylene crystals were described previously.At low magnifications the three types of polymer crystals appeared as slender rods. One type had a hexagonal cross section and the other two types had rectangular cross sections, that is, they were ribbonlike.

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A quantitative approach to inner shell losses

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010010977x ◽

1978 ◽

Vol 36 (1) ◽

pp. 526-527 ◽

Cited By ~ 2

Author(s):

R.D. Leapman ◽

P. Rez ◽

D.F. Mayers

Keyword(s):

Energy Transfer ◽

Cross Section ◽

Cross Sections ◽

Accurate Determination ◽

Background Intensity ◽

Core Excitation ◽

Quantitative Basis ◽

Cross Section Differential ◽

Bound Electrons

Microanalysis by EELS has been developing rapidly and though the general form of the spectrum is now understood there is a need to put the technique on a more quantitative basis (1,2). Certain aspects important for microanalysis include: (i) accurate determination of the partial cross sections, σx(α,ΔE) for core excitation when scattering lies inside collection angle a and energy range ΔE above the edge, (ii) behavior of the background intensity due to excitation of less strongly bound electrons, necessary for extrapolation beneath the signal of interest, (iii) departures from the simple hydrogenic K-edge seen in L and M losses, effecting σx and complicating microanalysis. Such problems might be approached empirically but here we describe how computation can elucidate the spectrum shape.The inelastic cross section differential with respect to energy transfer E and momentum transfer q for electrons of energy E0 and velocity v can be written as

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Oxygen K near edge structures studied with multiple scattering calculations

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100104583 ◽

1988 ◽

Vol 46 ◽

pp. 504-505

Author(s):

Xudong Weng ◽

Peter Rez

Keyword(s):

Cross Section ◽

Cross Sections ◽

Partial Cross Section ◽

Energy Window ◽

Edge Structure ◽

Fine Structures ◽

Hydrogenic Model ◽

Electron Energy Loss ◽

Quantitative Chemical

In electron energy loss spectroscopy, quantitative chemical microanalysis is performed by comparison of the intensity under a specific inner shell edge with the corresponding partial cross section. There are two commonly used models for calculations of atomic partial cross sections, the hydrogenic model and the Hartree-Slater model. Partial cross sections could also be measured from standards of known compositions. These partial cross sections are complicated by variations in the edge shapes, such as the near edge structure (ELNES) and extended fine structures (ELEXFS). The role of these solid state effects in the partial cross sections, and the transferability of the partial cross sections from material to material, has yet to be fully explored. In this work, we consider the oxygen K edge in several oxides as oxygen is present in many materials. Since the energy window of interest is in the range of 20-100 eV, we limit ourselves to the near edge structures.

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Absolute inner-shell cross section determination for EELS analysis

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010010473x ◽

1988 ◽

Vol 46 ◽

pp. 534-535

Author(s):

P.A. Crozier

Keyword(s):

Cross Section ◽

Cross Sections ◽

Absolute Cross Section ◽

Specimen Thickness ◽

Mass Thickness ◽

Scattering Cross ◽

Before And After ◽

Estimated Error ◽

Scattering Cross Sections ◽

Electron Microscopist

Absolute inelastic scattering cross sections or mean free paths are often used in EELS analysis for determining elemental concentrations and specimen thickness. In most instances, theoretical values must be used because there have been few attempts to determine experimental scattering cross sections from solids under the conditions of interest to electron microscopist. In addition to providing data for spectral quantitation, absolute cross section measurements yields useful information on many of the approximations which are frequently involved in EELS analysis procedures. In this paper, experimental cross sections are presented for some inner-shell edges of Al, Cu, Ag and Au.Uniform thin films of the previously mentioned materials were prepared by vacuum evaporation onto microscope cover slips. The cover slips were weighed before and after evaporation to determine the mass thickness of the films. The estimated error in this method of determining mass thickness was ±7 x 107g/cm2. The films were floated off in water and mounted on Cu grids.

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A technique for preparing semiconductor cross sections for both TEM and SEM analysis

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100155530 ◽

1989 ◽

Vol 47 ◽

pp. 712-713

Author(s):

Stanley J. Klepeis ◽

J.P. Benedict ◽

R.M Anderson

Keyword(s):

Sample Preparation ◽

Cross Section ◽

Cross Sections ◽

Sem Analysis ◽

Preparation Technique ◽

Ion Milling ◽

Tem Analysis ◽

Polished Cross Section ◽

Area Of Interest ◽

Polished Side

The ability to prepare a cross-section of a specific semiconductor structure for both SEM and TEM analysis is vital in characterizing the smaller, more complex devices that are now being designed and manufactured. In the past, a unique sample was prepared for either SEM or TEM analysis of a structure. In choosing to do SEM, valuable and unique information was lost to TEM analysis. An alternative, the SEM examination of thinned TEM samples, was frequently made difficult by topographical artifacts introduced by mechanical polishing and lengthy ion-milling. Thus, the need to produce a TEM sample from a unique,cross-sectioned SEM sample has produced this sample preparation technique.The technique is divided into an SEM and a TEM sample preparation phase. The first four steps in the SEM phase: bulk reduction, cleaning, gluing and trimming produces a reinforced sample with the area of interest in the center of the sample. This sample is then mounted on a special SEM stud. The stud is inserted into an L-shaped holder and this holder is attached to the Klepeis polisher (see figs. 1 and 2). An SEM cross-section of the sample is then prepared by mechanically polishing the sample to the area of interest using the Klepeis polisher. The polished cross-section is cleaned and the SEM stud with the attached sample, is removed from the L-shaped holder. The stud is then inserted into the ion-miller and the sample is briefly milled (less than 2 minutes) on the polished side. The sample on the stud may then be carbon coated and placed in the SEM for analysis.

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