Study of Critical Velocity of Stick-Slip Sliding

1960 ◽  
Vol 82 (4) ◽  
pp. 393-398 ◽  
Author(s):  
B. R. Singh
Keyword(s):  
Experimental Study ◽  
Theoretical Analysis ◽  
Critical Velocity ◽  
Mechanical Model ◽  
Analog Computer ◽  
Experimental Results ◽  
Milling Machine ◽  
Friction Damping ◽  
Stick Slip ◽  
Electric Analog

The motion of a body sliding under boundary friction, at a velocity slower than a particular critical velocity of the system, proceeds in a discontinuous or stick-slip form. This paper presents a theoretical analysis and an experimental study of the critical velocity of stick-slip sliding. The influence of various parameters such as friction, damping, stiffness, and sliding mass of the system on the critical velocity was studied on a mechanical model arranged on a milling machine. The arrangement was also simulated on an electric analog computer. Good correlation was observed between the theoretical values and the experimental results on the mechanical model and on the analog computer.

Experimental Study on Full-Scale Segment Model of Huaian Cable-Stayed Bridge Pylon

2011 ◽  
Vol 243-249 ◽  
pp. 1866-1870 ◽  
Author(s):  
Hong Yuan Tang ◽  
Shao Ping Meng
Keyword(s):  
Experimental Study ◽  
Stress Distribution ◽  
Theoretical Analysis ◽  
Full Scale ◽  
Experimental Results ◽  
Horizontal Load ◽  
Experiment Study ◽  
Segment Model ◽  
Cable Stayed Bridge

Through experiment study on full scale segmental model of Huaian bridge pylon, the stress distribution in the segmental model under the U shaped tendons and the horizontal load was measured. At the same time, the critical cracking load and the coefficient cracking safety class of the anchorage zone were obtained. At last, the theoretical analysis was compared with the experimental results, the theory agreed with the experiment well.

Theoretical and Experimental Study on Crystal Detachment from a Chilling Surface with Vibration

2014 ◽  
Vol 490-491 ◽  
pp. 172-176
Author(s):  
Wen Li Wang ◽  
Rui Zhao Xu ◽  
Xue Jun Chang
Keyword(s):  
Experimental Study ◽  
Solid Surface ◽  
Vibration Frequency ◽  
Mechanical Model ◽  
Theoretical Study ◽  
Mechanical Analysis ◽  
Primary Phase ◽  
Experimental Results ◽  
Cooling Temperature ◽  
Main Factors

A model of crystal detachment from a chilling solid surface with vibration has been presented according to the mechanical analysis of the primary phase of a growing crystal grain. The model indicates that the main factors of crystal detachment are vibration frequency and amplitude as well as cooling temperature of the chilling solid surface. The effects of the above three factors on the actual crystal detachment behaviors were studied experimentally by using a transparent NH4Cl-70%wtH2O alloy. The consistency between the experimental results and theoretical study proves the mechanical model.

scholarly journals Response of round-hole tubes submitted to pure bending creep and pure bending relaxation

2021 ◽  
Vol 13 (9) ◽  
pp. 168781402110491
Author(s):  
Kuo-Long Lee ◽  
Bo-You Liu ◽  
Wen-Fung Pan
Keyword(s):  
Experimental Study ◽  
Aluminum Alloy ◽  
Theoretical Analysis ◽  
Research Team ◽  
Hole Diameter ◽  
Thickness Ratio ◽  
Experimental Results ◽  
Round Hole ◽  
Pure Bending ◽  
Time Relationship

This paper presents experimental study on the response of 6061-T6 aluminum alloy round-hole tubes with five different hole diameters of 2, 4, 6, 8, and 10 mm and four different diameter-to-thickness ratios of 30, 40, 50, and 60 submitted to pure bending creep and pure bending relaxation. Pure bending creep or relaxation is defined as bending the tube to the required moment or curvature and maintaining that moment or curvature for a period of time. The experimental results of pure bending creep show that the curvature increases with time. In addition, larger holding moment, diameter-to-thickness ratio, or hole diameter results in larger creep curvature. As the curvature continues to increase, the round-hole tube eventually breaks. The experimental results of pure bending relaxation show that the relaxation moment decreases sharply with time and tends to a stable value. In addition, larger holding curvature, diameter-to-thickness ratio, or hole diameter results in larger drop of the relaxation moment. Due to fixed curvature, the round-hole tube does not break. Finally, formulas proposed by the research team of Pan et al. were respectively improved to simulate the creep curvature-time relationship for pure bending creep in the initial and the secondary stages and the relaxation moment-time for pure bending relaxation. After comparing with the experimental results, it is found that theoretical analysis can reproduce the experimental results reasonably.

scholarly journals Experimental Study on the Nonlinear Vibrations and n× Amplitudes of a Rotor With a Transverse Crack

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
Jean-Jacques Sinou
Keyword(s):  
Experimental Study ◽  
Theoretical Analysis ◽  
Monitoring System ◽  
Nonlinear Response ◽  
Transverse Crack ◽  
Nonlinear Vibrations ◽  
Rotor System ◽  
Experimental Results ◽  
Frequency Components ◽  
On Line

In this paper, the nonlinear response of a rotor system containing a transverse crack is analyzed experimentally in order to propose a nondestructive detection of cracks in the rotor. More particularly, the evolutions of the n× superharmonic frequency components at the various subcritical resonant peaks and the decrease in the subcritical resonant speeds are investigated for various crack depths. The experimental results that are presented in this study confirm the theoretical analysis of many researchers and provide a possible basis for an on-line monitoring system.

Theoretical Analysis and Experimental Study of Strength Matching between Mortarless Grouted Concrete and Block Material

2013 ◽  
Vol 368-370 ◽  
pp. 1022-1026
Author(s):  
Ming Song Yi ◽  
Yan Qiu Xu ◽  
Ni Lou ◽  
Lan Ying Zhang ◽  
Guo Hui Yi
Keyword(s):  
Experimental Study ◽  
Compressive Strength ◽  
Theoretical Analysis ◽  
Experimental Results ◽  
Joint Work ◽  
Matching Problem ◽  
Nonlinear Simulation ◽  
Strength Grade

In order to solve the strength matching problem of grouted concrete and block in mortarless grouted masonry, the article adopts the ANSYS nonlinear simulation to establish different strength grade models. And the result shows that, when the strength matching relationship between the mortarless block and the concrete reaches fc/fb=1~2, the grouted concrete and block compressive strength are brought into full play without material waste. The result is close to fcu/fcb = 1.5~3.5 (gross area) from the literature[1]. It is clear that, when the compressive strength of the two is close, their joint work can exert the best effects. It fits the experimental results and provides reference to the application of mortarless grouted block.

scholarly journals Theoretical and Experimental Study of Split Semi Horse Shoe Structure

2018 ◽  
Vol 7 (5) ◽  
pp. 131-136
Author(s):  
G. Singh ◽  
S. S. Pattnaik
Keyword(s):  
Experimental Study ◽  
Theoretical Analysis ◽  
Equivalent Circuit ◽  
Radiation Pattern ◽  
Patch Antenna ◽  
Circuit Theory ◽  
Experimental Results ◽  
Effective Parameters ◽  
Metamaterial Structure ◽  
Good Agreement

In this paper a new planar metamaterial structure that looks like semi-horse shoe in shape (SSHSS) is designed and simulated. Theoretical analysis of proposed structure done using equivalent circuit theory. Medium effective parameters are extracted using modified NRW approach which proved the metamaterial property of the new unit cell. Radiation pattern, directivity and gain of the new structure were illustrated which gives the possibility of using SSHSS as the antenna. Proposed structure shows multiband characteristics. This antenna shows high directivity (7.92 dBi, 7.86 dBi, 10.11 dBi) and moderate gain (2.55 dBi, 3.90 dBi, 5.07 dBi) at 5.83 GHz, 8.41 GHz, 10.68 GHz respectively. RT duroid is used for fabrication of prototype of the proposed structure. This new structure can be used as metamaterial inspired antenna as well as normal patch antenna. Experimental results shows good agreement with simulated and theoretical results.The proposed structure has been simulated using IE3D electromagnetic simulator.

Theoretical and Experimental Study on the Wave Propagation through a Micro Gap

2011 ◽  
Vol 346 ◽  
pp. 508-514
Author(s):  
Xiao Yun Chen ◽  
Gui Lan Yu ◽  
Wei Wei Cao ◽  
Wen Tao Qiang
Keyword(s):  
Experimental Study ◽  
Wave Propagation ◽  
Theoretical Analysis ◽  
Nondestructive Evaluation ◽  
Normal Incidence ◽  
Experimental Results ◽  
Harmonic Waves ◽  
Flat Interface ◽  
Gap Width

In the present paper, a preliminary exploration which includes the theoretical analysis and experimental study on the wave propagation through a micro gap was carried out. Harmonic waves, normal incidence, smooth and flat interface were taken into account. The theoretical and experimental results both show that the initial gap width has significant influences on the harmonics. Their relations may be effective on nondestructive evaluation of a pre-existing gap.

Mechanism analysis and prediction of explosive formed projectile’s axial fracture

2021 ◽  
Author(s):  
Li Ding ◽  
Jianwei Jiang ◽  
Shuyou Wang ◽  
Liuqi Ji
Keyword(s):  
Theoretical Analysis ◽  
Critical Velocity ◽  
Velocity Gradient ◽  
Wave Theory ◽  
Axial Direction ◽  
Experimental Results ◽  
Model Parameters ◽  
Mechanism Analysis ◽  
Long Rod ◽  
Axial Fracture

To explain the axial fracture phenomenon of Explosively Formed Projectile (EFP), the fracture mechanism of long rod EFP during the forming phase is analyzed by the stress wave theory. When the velocity gradient [Formula: see text] between the head and tail parts exceeds the critical value [Formula: see text], the EFP would fracture in the axial direction. Based on the Johnson–Cook constitutive model parameters and the special conditions in the forming phase of EFP, the critical velocity gradient [Formula: see text] can be determined by theoretical calculation and then validated by experimental results for both copper and tantalum EFPs. The experimental results for EFP’s fracture agree well with the prediction of the theoretical analysis. The theoretical analysis method can be applied as an important measure to determine the critical velocity gradient and predict the fracture of long rod EFP, providing reference for the application of new kinds of high density materials in the EFP research area.

PHOTOINDUCED NONLINEAR OCTUPOLAR POLARIZATION: TRANSIENT AND PERMANENT REGIMES

1996 ◽  
Vol 05 (04) ◽  
pp. 653-670 ◽  
Author(s):  
CÉLINE FIORINI ◽  
JEAN-MICHEL NUNZI ◽  
FABRICE CHARRA ◽  
IFOR D.W. SAMUEL ◽  
JOSEPH ZYSS
Keyword(s):  
Theoretical Analysis ◽  
Second Harmonic ◽  
Experimental Results ◽  
Polar Field ◽  
Rotational Spectrum ◽  
Dual Frequency ◽  
One Dimensional ◽  
Ethyl Violet ◽  
Disperse Red 1 ◽  
Good Agreement

An original poling method using purely optical means and based on a dual-frequency interference process is presented. We show that the coherent superposition of two beams at fundamental and second-harmonic frequencies results in a polar field with an irreducible rotational spectrum containing both a vector and an octupolar component. This enables the method to be applied even to molecules without a permanent dipole such as octupolar molecules. After a theoretical analysis of the process, we describe different experiments aiming at light-induced noncentrosymmetry performed respectively on one-dimensional Disperse Red 1 and octupolar Ethyl Violet molecules. Macroscopic octupolar patterning of the induced order is demonstrated in both transient and permanent regimes. Experimental results show good agreement with theory.

scholarly journals Experimental study of the $ \gamma p \rightarrow K^{0}\Sigma^{+}$, $ \gamma n \rightarrow K^{0} \Lambda$, and $ \gamma n \rightarrow K^{0} \Sigma^{0}$ reactions at the Mainz Microtron

2019 ◽  
Vol 55 (11) ◽  
Author(s):  
C. S. Akondi ◽  
K. Bantawa ◽  
D. M. Manley ◽  
S. Abt ◽  
P. Achenbach ◽  
...  
Keyword(s):  
Experimental Study ◽  
Cross Sections ◽  
Differential Cross ◽  
Legendre Polynomials ◽  
Neutral Kaon ◽  
Experimental Results ◽  
Differential Cross Sections ◽  
Theoretical Predictions ◽  
Photoproduction Reactions ◽  
Insight Into

Abstract.This work measured $ \mathrm{d}\sigma/\mathrm{d}\Omega$dσ/dΩ for neutral kaon photoproduction reactions from threshold up to a c.m. energy of 1855MeV, focussing specifically on the $ \gamma p\rightarrow K^0\Sigma^+$γp→K0Σ+, $ \gamma n\rightarrow K^0\Lambda$γn→K0Λ, and $ \gamma n\rightarrow K^0 \Sigma^0$γn→K0Σ0 reactions. Our results for $ \gamma n\rightarrow K^0 \Sigma^0$γn→K0Σ0 are the first-ever measurements for that reaction. These data will provide insight into the properties of $ N^{\ast}$N* resonances and, in particular, will lead to an improved knowledge about those states that couple only weakly to the $ \pi N$πN channel. Integrated cross sections were extracted by fitting the differential cross sections for each reaction as a series of Legendre polynomials and our results are compared with prior experimental results and theoretical predictions.

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