scholarly journals Experimental Research on Influencing Factors of Surface Friction Coefficient of Solar PV Panels

2018 ◽  
Vol 146 ◽  
pp. 012038
Author(s):  
Zhang Dan ◽  
Zhao Mingzhi
Keyword(s):  
Friction Coefficient ◽  
Influencing Factors ◽  
Experimental Research ◽  
Surface Friction ◽  
Solar Pv

Study on the Mechanical Properties and Handle of PTT/Wool Blended Fabrics

2010 ◽  
Vol 150-151 ◽  
pp. 1810-1813
Author(s):  
Guang Biao Xu ◽  
Lian Ying Zhao ◽  
Fu Mei Wang
Keyword(s):  
Mechanical Properties ◽  
Friction Coefficient ◽  
Surface Friction ◽  
Maximum Load ◽  
Wool Fabrics

The low-stress properties of PTT/wool blended fabrics were investigated by comparing with PET/wool blended fabrics. The results show that, the elongation of PTT/wool fabrics at the maximum load is higher, especially in filling wise, which means PTT/wool fabrics have better elastic. The bending hysteresis, shearing rigidity and shearing hysteresis of PTT/wool fabrics are higher than those of PET/wool fabrics, determining the fabrics having good formability. PTT/wool fabrics are easier to be compressed, and has a little higher surface friction coefficient, giving the fabrics better feeling of softness and fullness. The hand values show that PTT/wool blended fabrics are softer, and have the good bulkiness but not as good as that of PET/wool fabrics.

Slip-Clutch Torque Estimation via Real-Time Adaptive Lookup Table

2021 ◽  
Vol 2 (2) ◽  
Author(s):  
Wenpeng Wei ◽  
Hussein Dourra ◽  
Guoming Zhu
Keyword(s):  
Friction Coefficient ◽  
Real Time ◽  
Mean Squared Error ◽  
Surface Friction ◽  
Lookup Table ◽  
Recursive Least Squares ◽  
Time Varying ◽  
Squared Error ◽  
Output Torque ◽  
Clutch Torque

Abstract Transfer case clutch is crucial in determining traction torque distribution between front and rear tires for four-wheel-drive (4WD) vehicles. Estimating time-varying clutch surface friction coefficient is critical for traction torque control since it is proportional to the clutch output torque. As a result, this paper proposes a real-time adaptive lookup table strategy to provide the time-varying clutch surface friction coefficient. Specifically, the clutch-parameter-dependent (such as clutch output torque and clutch touchpoint distance) friction coefficient is first estimated with available low-cost vehicle sensors (such as wheel speed and vehicle acceleration); and then a clutch-parameter-independent approach is developed for clutch friction coefficient through a one-dimensional lookup table. The table nodes are adaptively updated based on a fast recursive least-squares (RLS) algorithm. Furthermore, the effectiveness of adaptive lookup table is demonstrated by comparing the estimated clutch torque from adaptive lookup table with that estimated from vehicle dynamics, which achieves 14.8 Nm absolute mean squared error (AMSE) and 2.66% relative mean squared error (RMSE).

scholarly journals Dynamic characteristics of the gear-rotor system in compressed air energy storage considering friction effects

2021 ◽  
Vol 12 (1) ◽  
pp. 677-688
Author(s):  
Xinran Wang ◽  
Wen Li ◽  
Dongxu Hu ◽  
Xingjian Dai ◽  
Haisheng Chen
Keyword(s):  
Energy Storage ◽  
Friction Coefficient ◽  
Dynamic Characteristics ◽  
Surface Friction ◽  
Rotor System ◽  
Compressed Air ◽  
Contact Temperature ◽  
Tooth Surface ◽  
Compressed Air Energy Storage ◽  
Rotating Speed

Abstract. The tooth surface friction effects and the resulting tooth surface contact temperature are important factors for the dynamic characteristics of a gear-rotor system in compressed air energy storage (CAES). Therefore, a 3∘ of freedom finite-element model of the system is set up in which the lubrication state of the gear pair, tooth surface friction, contact temperature of the tooth surface, backlash and unbalanced excitation are considered. The friction coefficient is calculated according to the variation of the lubrication state, and the tooth surface contact temperature is derived based on the friction coefficient. The tooth profile deformation caused by the change in the contact temperature is calculated, and the resulting effects on backlash and comprehensive meshing stiffness are considered. The influence of rotating speed, torque load and viscosity of lubricating oil on the system response is studied, and the variation of the friction coefficient, flash temperature of the tooth surface, pressure of the tooth surface and so on are discussed in detail. The results indicate that when the friction coefficient is derived according to the variation of the lubrication state, the variation of the contact temperature of the tooth surface with rotating speed is quite different from that calculated based on a friction coefficient which is set artificially. This leads to a new variation of the dynamic response of the gear-rotor system, and the method of stabilizing the operation of the system is put forward based on the optimization curve for the operation of the system. The results obtained in this paper will provide a reference for the study and design of a gear-rotor system in CAES.

Experimental Research on Water Cushion Belt Conveyor

2013 ◽  
Vol 431 ◽  
pp. 88-92
Author(s):  
Ai Dong Zhang ◽  
Ri Cheng Xu ◽  
Yun Meng ◽  
Xun Fan
Keyword(s):  
Experimental Study ◽  
Influencing Factors ◽  
Experimental Research ◽  
Industrial Application ◽  
Theoretical Basis ◽  
Belt Conveyor ◽  
New Type ◽  
Air Cushion

Water cushion belt conveyor is a new type of continuous conveyor which develops from belt conveyor and air cushion belt conveyor .By experimental research on water cushion belt conveyor ,we can observe the condition of water cushion and accomplish the date acquisition of water cushion pressure .Analyzing the pressure ,we can get influencing factors of water cushion pressure and verify the feasibility of industrial application of water cushion belt conveyor .Combining theory study with experimental study ,provide theoretical basis and guide for the further progress of water cushion belt conveyor .

scholarly journals Study on Friction and Lubrication Characteristics of Surface with Unidirectional Convergence Texture

Coatings ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 780 ◽  
Author(s):  
Chenchen Li ◽  
Xuefeng Yang ◽  
Shouren Wang ◽  
Yanjun Wang ◽  
Chongyang Lu ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Abrasive Wear ◽  
Simulation Analysis ◽  
Dynamic Pressure ◽  
Contact Fatigue ◽  
Hydrodynamic Pressure ◽  
Surface Friction ◽  
Textured Surface ◽  
Fatigue Wear ◽  
Lubrication Performance

In order to study the influence of texture on the wear and lubrication performance of the surface of the tools, three kinds of textures with unidirectional convergence morphology were processed on the surface of the samples, and each texture was designed with different area occupancy ratios. Simulation analysis shows that, owing to the reflow and convection effect of liquid in the texture, the lubricating film flowing through the textured surface has a high hydrodynamic pressure value, and the semicircular ring texture is the most prominent. By comparing the friction coefficient, when the area occupancy ratio of texture on the surface is 10%, the surface of the samples with different morphology has the lowest coefficient of friction; the friction coefficient of the semicircular ring textured surface is especially very low. Surface textures reduce the direct contact area between the friction pairs, and generate dynamic pressure lubrication and secondary lubrication, so that the surface friction coefficient of the samples is obviously reduced. The surfaces of the non-textured samples have abrasive wear and contact fatigue wear, and the surfaces of the textured samples have adhesive wear, abrasive wear, and cavitation.

scholarly journals Study on bifurcation characteristics of multi-clearance bending torsional coupling gear transmission based on EHL

2020 ◽  
Vol 12 (6) ◽  
pp. 168781402093750
Author(s):  
Hao Dong ◽  
Jianwen Zhang ◽  
Libang Wang
Keyword(s):  
Friction Coefficient ◽  
Periodic Motion ◽  
Chaotic Motion ◽  
Hydrodynamic Lubrication ◽  
Surface Friction ◽  
Tooth Surface ◽  
Time Varying ◽  
Mesh Stiffness ◽  
Vibration Model ◽  
Non Linear

In order to study the influence of tooth surface friction on the non-linear bifurcation characteristics of multi-clearance gear drive system, a 6 degree-of-freedom bending torsional coupled vibration model was established. The time-varying mesh stiffness, backlash, support clearance and damping were considered comprehensively in this non-linear vibration model. Loaded tooth contact analysis was used to calculate the time-varying mesh stiffness. Based on the elasto-hydrodynamic lubrication, the time-varying friction coefficient was calculated. Runge–Kutta numerical method was used to solve the dimensionless dynamic differential equation. Using phase diagram, Poincaré diagram, time history diagram, and spectrum diagram, the influence of tooth surface friction on bifurcation characteristics was studied. The results show that the system undergoes a change from 1-periodic motion, multi-periodic motion, to chaotic motion through bifurcation and catastrophe when the speed changes independently. When the friction coefficient of tooth surface changes from 0, 0.05 to 0.09, the chaotic motion of the system is suppressed. Similarly, with the increase in tooth friction, the chaotic motion characteristics are suppressed. Tooth surface friction is the main factor affecting chaotic motion. With the increase in friction coefficient of tooth surface, the chaos characteristic does not change obviously and the vibration amplitude decreases slightly.

Switchable Friction Coefficient on Shape Memory Photonic Crystals

MRS Advances ◽  
2020 ◽  
Vol 5 (14-15) ◽  
pp. 757-763
Author(s):  
Yifan Zhang ◽  
Xingyi Lyu ◽  
Yongliang Ni ◽  
Diyang Li ◽  
Sin-Yen Leo ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Photonic Crystal ◽  
Friction Coefficient ◽  
Photonic Crystals ◽  
Shape Memory ◽  
Intelligent Control ◽  
Surface Friction ◽  
Soft Robotics ◽  
Sliding Test ◽  
Sensor Interfaces

ABSTRACTIntelligent control of friction and adhesion has attracted much attention for use in soft robotics, human-sensor interfaces, and bionics. Here we introduce a shape memory photonic crystal (SMPC) polymer that can be programmed and recovered by solvent to realize switchable surface friction. Micro sliding test show that the friction coefficient on this SMPC in the programmed and recovered state can vary by three times. We also show that the mechanism behind this switchable friction coefficient is the surface roughness related adhesion.

656 The influence of road surface friction coefficient on the effect of Collision Mitigation Brake : Investigation by using vehicle collision simulation

2009 ◽  
Vol 2009 (0) ◽  
pp. _656-1_-_656-6_
Author(s):  
Hirofumi MINAMOTO ◽  
Tetsushi MIMURO ◽  
Toshiya YOSHITANI ◽  
Koji SATO ◽  
Takeshi WATANABE ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Surface Friction ◽  
Road Surface ◽  
Vehicle Collision ◽  
Collision Mitigation
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