Self-Excitation in Guided Circular Saws

1988 ◽  
Vol 110 (3) ◽  
pp. 338-344 ◽  
Author(s):  
B. F. Lehmann ◽  
S. G. Hutton
Keyword(s):  
Analytical Model ◽  
Analytical Study ◽  
Design Tool ◽  
The Self ◽  
Experimental Results ◽  
Vibrational Characteristics ◽  
Guide System ◽  
Circular Saws

The paper presents the results of an experimental and analytical study into the vibrational characteristics of guided rotating saw blades that are not perfectly flat. Experimental results are presented that show the nature of the vibrations induced by the interaction between the guides and the blade. An analytical model is developed that includes the effect of the interaction between the guide and the blade, and this model may be used as a design tool in avoiding the self-excited resonances that exist in the coupled blade/guide system.

Vibration Characteristics of Guided Circular Saws: Experimental and Numerical Analyses

2012 ◽  
Vol 134 (6) ◽  
Author(s):  
Ramin M. H. Khorasany ◽  
Ahmad MohammadPanah ◽  
Stanley G. Hutton
Keyword(s):  
Rigid Body ◽  
External Force ◽  
Plate Theory ◽  
Lateral Displacement ◽  
Experimental Results ◽  
Experimental Investigations ◽  
Governing Equations ◽  
Air Jet ◽  
Vibrational Characteristics ◽  
Circular Saws

Studying the vibrational characteristics of guided circular saws is of particular interest in the current study. Guided circular saws are free in both the inner and outer rim. They are restrained from having axial motion by using two space-fixed guide pads in either side of the blade. Because of the small clearance between the guide pads and the saw blade, the blade is capable of having rigid body tilting and a translational degree of freedom. At first, we attempted to develop an understanding regarding the vibrational characteristics of such disks through experimental investigations. An electromagnet was used to generate random white noise for the purpose of exciting the bending waves. Using inductance displacement probes, the frequencies and amplitudes of the disk vibrations were measured and the mean deflections were plotted. In the next step, a space-fixed external force (air jet) was used to excite the disks in the lateral direction. The experimental results indicate that the blade frequencies show a significant change as a result of the initial lateral displacement imposed by the external force. It was also seen that due to the presence of the external force, a stationary wave develops and collapses at a higher speed. For the numerical simulations, the nonlinear governing equations based on Von Kármán plate theory were used. The effect of rigid body degrees of freedom was taken into account. As an approximation, the guide pads were modeled with four space-fixed springs. Using Galerkin’s method, the governing equations were discretized and their equilibrium solutions were found. After linearizing the governing equations around the equilibrium solution, the effect of nonlinearity on the amplitude and frequency response of the guided blade was investigated. It was seen that the numerical results were in close agreement with the experimental results.

Lateral Tire Forces on Wet Roads

1977 ◽  
Vol 5 (2) ◽  
pp. 75-82 ◽  
Author(s):  
A. Schallamach
Keyword(s):  
Normal Load ◽  
The Self ◽  
Experimental Results ◽  
Slip Angle ◽  
Tire Model ◽  
Side Force ◽  
Tire Forces

Abstract Expressions are derived for side force and self-aligning torque of a simple tire model on wet roads with velocity-dependent friction. The results agree qualitatively with experimental results at moderate speeds. In particular, the theory correctly predicts that the self-aligning torque can become negative under easily realizable circumstances. The slip angle at which the torque reverses sign should increase with the normal load.

scholarly journals Generalized analytical model based on harmonic coupling for hybrid plasmonic modes: comparison with numerical and experimental results

2015 ◽  
Vol 23 (21) ◽  
pp. 27376 ◽  
Author(s):  
Mitradeep Sarkar ◽  
Jean-François Bryche ◽  
Julien Moreau ◽  
Mondher Besbes ◽  
Grégory Barbillon ◽  
...  
Keyword(s):  
Analytical Model ◽  
Experimental Results ◽  
Model Based

Convective Losses From Cavity Solar Receivers—Comparisons Between Analytical Predictions and Experimental Results

1983 ◽  
Vol 105 (1) ◽  
pp. 29-33 ◽  
Author(s):  
A. M. Clausing
Keyword(s):  
Experimental Data ◽  
Experimental Evidence ◽  
Analytical Model ◽  
Excellent Agreement ◽  
Experimental Results ◽  
Simple Analytical Model ◽  
Refined Model ◽  
Wall Area

Cavity solar receivers are generally believed to have higher thermal efficiencies than external receivers due to reduced losses. A simple analytical model was presented by the author which indicated that the ability to heat the air inside the cavity often controls the convective loss from cavity receivers. Thus, if the receiver contains a large amount of inactive hot wall area, it can experience a large convective loss. Excellent experimental data from a variety of cavity configurations and orientations have recently become available. These data provided a means of testing and refining the analytical model. In this manuscript, a brief description of the refined model is presented. Emphasis is placed on using available experimental evidence to substantiate the hypothesized mechanisms and assumptions. Detailed comparisons are given between analytical predictions and experimental results. Excellent agreement is obtained, and the important mechanisms are more clearly delineated.

scholarly journals Adaptive Broadcasting Mechanism for Bandwidth Allocation in Mobile Services

2014 ◽  
Vol 2014 ◽  
pp. 1-14
Author(s):  
Gwo-Jiun Horng ◽  
Chi-Hsuan Wang ◽  
Chih-Lun Chou
Keyword(s):  
Analytical Model ◽  
Bandwidth Allocation ◽  
Data Dissemination ◽  
Data Access ◽  
Experimental Results ◽  
Bandwidth Utilization ◽  
Access Latency ◽  
The Mean ◽  
Access Efficiency ◽  
Broadcast Program

This paper proposes a tree-based adaptive broadcasting (TAB) algorithm for data dissemination to improve data access efficiency. The proposed TAB algorithm first constructs a broadcast tree to determine the broadcast frequency of each data and splits the broadcast tree into some broadcast wood to generate the broadcast program. In addition, this paper develops an analytical model to derive the mean access latency of the generated broadcast program. In light of the derived results, both the index channel’s bandwidth and the data channel’s bandwidth can be optimally allocated to maximize bandwidth utilization. This paper presents experiments to help evaluate the effectiveness of the proposed strategy. From the experimental results, it can be seen that the proposed mechanism is feasible in practice.

RAMAN SPECTRA OF THE H2SO4–SO3 AND D2SO4–SO3 SYSTEMS: EVIDENCE FOR THE OCCURRENCE OF POLYSULPHURIC ACIDS

1962 ◽  
Vol 40 (4) ◽  
pp. 658-674 ◽  
Author(s):  
R. J. Gillespie ◽  
E. A. Robinson
Keyword(s):  
Sulphuric Acid ◽  
Raman Spectra ◽  
Ionic Species ◽  
The Self ◽  
Experimental Results ◽  
Similar Work ◽  
Stretching Vibrations ◽  
Sulphur Trioxide ◽  
High Concentrations

The Raman spectra of oleums, i.e. mixtures of sulphur trioxide and sulphuric acid, have been re-examined. Similar measurements on the sulphur trioxide – deuterosulphuric acid (D2SO4) system are also reported. The experimental results and conclusions of previous similar work on oleums are discussed. By comparison of the spectra of oleums with those of the polysulphuryl halides it is shown that the polysulphuric acids H2S2O7 and H2S3O10 are present in this system. The increase in the frequency of the SO2 stretching vibrations with increasing concentration of sulphur trioxide gives evidence for the existence of higher polysulphuric acids such as H2S4O13 at high concentrations of sulphur trioxide. In relatively concentrated oleum, sulphur trioxide monomer and trimer are also present. It is shown that the self-dissociation of liquid H2S2O7 gives mainly molecular H2S2O10 and H2SO4 and not ionic species. The conclusions reached from the interpretation of the Raman spectra of the D2SO4–SO3 system are similar to those arrived at for sulphuric acid oleums. The spectra of solutions of NaHSO4 in oleums were also examined, and are discussed.

scholarly journals A Self-Supervised Tibetan-Chinese Vocabulary Alignment Method based on Adversarial Learning

2021 ◽  
Author(s):  
Enshuai Hou ◽  
Jie zhu
Keyword(s):  
The Self ◽  
Experimental Results ◽  
Chinese Characters ◽  
Training Method ◽  
Alignment Method ◽  
Adversarial Learning ◽  
Semantic Correlation ◽  
Data Alignment ◽  
Similarity Calculation ◽  
Adversarial Training

Tibetan is a low-resource language. In order to alleviate the shortage of parallel corpus between Tibetan and Chinese, this paper uses two monolingual corpora and a small number of seed dictionaries to learn the semi-supervised method with seed dictionaries and self-supervised adversarial training method through the similarity calculation of word clusters in different embedded spaces and puts forward an improved self-supervised adversarial learning method of Tibetan and Chinese monolingual data alignment only. The experimental results are as follows. First, the experimental results of Tibetan syllables Chinese characters are not good, which reflects the weak semantic correlation between Tibetan syllables and Chinese characters; second, the seed dictionary of semi-supervised method made before 10 predicted word accuracy of 66.5 (Tibetan - Chinese) and 74.8 (Chinese - Tibetan) results, to improve the self-supervision methods in both language directions have reached 53.5 accuracy.

scholarly journals Experimental Study and Extended Finite Element Simulation of Fracture of Self-Compacting Rubberized Concrete

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Xinquan Wang ◽  
Hongguo Diao ◽  
Yunliang Cui ◽  
Changguang Qi ◽  
Shangyu Han
Keyword(s):  
Finite Element ◽  
Loading Rate ◽  
High Performance Concrete ◽  
The Self ◽  
Experimental Results ◽  
Crack Mouth Opening Displacement ◽  
Displacement Curve ◽  
Rubberized Concrete ◽  
Extended Finite Element ◽  
Self Compacting Concrete

Self-compacting rubberized concrete (SCRC) is a high-performance concrete that can achieve compacting effect by self-gravity without vibration during pouring. Because of its excellent fluidity, homogeneity, and stability, the application of self-compacting concrete in engineering can improve work efficiency and reduce project cost. The effects of loading rate on the fracture behavior of self-compacting concrete were studied in this paper. Three-point bend (TPB) tests were carried out at five loading rates of 1, 0.1, 0.001, 0.0001, and 0.00001 mm/s. The dimensions of the specimens were 100  mm × 100 mm × 400 mm. A precast crack was set in the middle of the specimen with a notch-depth ratio of 0.4. The experimental results show that the peak load on the load-CMOD (crack mouth opening displacement) curve gradually increases with the increase of the loading rate. Although the fracture energy a presented greater dispersion under the loading rate of 1 mm/s, the overall changes were still rising with the increase of the loading rate. Besides studying the softening characteristics of the self-compacting concrete, the constitutive softening curve of the self-compacting concrete was obtained using the bilinear model. Finally, curved three-point bending beams were simulated by using the extended finite element method based on ABAQUS. The fracture process of the self-compacting concrete under different loading conditions was analyzed more intuitively. The simulation results were compared with the experimental results, and the same conclusions were obtained.

scholarly journals Multivariate Self-Dual Morphological Operators Based on Extremum Constraint

2015 ◽  
Vol 2015 ◽  
pp. 1-16
Author(s):  
Tao Lei ◽  
Yi Wang ◽  
Weiwei Luo
Keyword(s):  
Noise Removal ◽  
Complete Characterization ◽  
The Self ◽  
Experimental Results ◽  
Watershed Transformation ◽  
Morphological Operators ◽  
Self Duality ◽  
Multichannel Images ◽  
Duality Property ◽  
Image Details

Self-dual morphological operators (SDMO) do not rely on whether one starts the sequence with erosion or dilation; they treat the image foreground and background identically. However, it is difficult to extend SDMO to multichannel images. Based on the self-duality property of traditional morphological operators and the theory of extremum constraint, this paper gives a complete characterization for the construction of multivariate SDMO. We introduce a pair of symmetric vector orderings (SVO) to construct multivariate dual morphological operators. Furthermore, utilizing extremum constraint to optimize multivariate morphological operators, we construct multivariate SDMO. Finally, we illustrate the importance and effectiveness of the multivariate SDMO by applications of noise removal and segmentation performance. The experimental results show that the proposed multivariate SDMO achieves better results, and they suppress noises more efficiently without losing image details compared with other filtering methods. Moreover, the proposed multivariate SDMO is also shown to have the best segmentation performance after the filtered images via watershed transformation.

Ion acceleration by multiple laser pulses and their spontaneous electromagnetic fields in plasma

2008 ◽  
Vol 74 (1) ◽  
pp. 111-118
Author(s):  
FEN-CE CHEN
Keyword(s):  
Magnetic Fields ◽  
Electric Field ◽  
Analytical Model ◽  
Electromagnetic Fields ◽  
Equations Of Motion ◽  
Charged Particles ◽  
Laser Pulses ◽  
The Self ◽  
Electric And Magnetic Fields ◽  
Relativistic Equations

AbstractThe acceleration of ions by multiple laser pulses and their spontaneously generated electric and magnetic fields is investigated by using an analytical model for the latter. The relativistic equations of motion of test charged particles are solved numerically. It is found that the self-generated axial electric field plays an important role in the acceleration, and the energy of heavy test ions can reach several gigaelectronvolts.

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