Research on ground surface characteristics of prism-plane sapphire under the orthogonal grinding direction

2019 ◽  
Vol 489 ◽  
pp. 802-814 ◽  
Author(s):  
Wenxiang Zhao ◽  
Yinhui Wang ◽  
Zhiqiang Liang ◽  
Tianfeng Zhou ◽  
Xibin Wang ◽  
...  
Keyword(s):  
Ground Surface ◽  
Surface Characteristics ◽  
Prism Plane

A Three-Dimensional Fractal Analysis Method for Ground Monocrystal Sapphire Surface

2014 ◽  
Vol 1017 ◽  
pp. 187-192
Author(s):  
Qiu Yan Wang ◽  
Zhi Qiang Liang ◽  
Xi Bin Wang ◽  
Wen Xiang Zhao ◽  
Yong Bo Wu ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Fractal Dimension ◽  
Fractal Analysis ◽  
Three Dimensional ◽  
Ground Surface ◽  
Surface Characteristics ◽  
Surface Phenomenon ◽  
Analysis Method ◽  
Characterization Methods ◽  
Box Counting

Conventional characterization methods of grinding surface using surface roughness parameters, e.g., Ra, depend on either the resolution of the measuring instrument or the length of the sample. But fractal dimension (FD) as a scale-independent fractal parameter is effective to evaluate the ground surface at any length scale and represent lots of surface phenomenon at its relevant length scales. In this paper, a three-dimensional (3D) box-counting fractal analysis method is used to investigate ground surface morphology of monocrystal sapphire by calculating 3D fractal dimension of the ground surface. The results obtained show that fractal dimension decreases with the increasing surface roughness. For the ground surface with higher fractal dimension, its microtopography is more exquisite with minor defects. Once the fractal dimension become smaller, deep cracks and pronounced defects are exhibited in ground surface. Moreover, the ground surface obtained in ductile mode has much higher fractal dimension than that in brittle mode. Therefore, the fractal analysis method has the potential to reveal the ground surface characteristics of monocrystal sapphire.

scholarly journals Research in Meteorological Modeling Oriented Comprehensive Surface Complexity (CSC)

2019 ◽  
Vol 11 (15) ◽  
pp. 4081
Author(s):  
Chunxiao Zhang ◽  
Xinqi Zheng ◽  
Jiayang Li ◽  
Shuxian Wang ◽  
Weiming Xu
Keyword(s):  
Ground Surface ◽  
Window Size ◽  
Surface Characteristics ◽  
Absolute Error ◽  
Multiple Regression Model ◽  
Landscape Patterns ◽  
Topographic Complexity ◽  
Meteorological Simulation ◽  
Meteorological Modeling ◽  
Wrf Modeling

Ground surface characteristics (i.e., topography and landscape patterns) are important factors in geographic dynamics. Thus, the complexity of ground surface is a valuable indicator for designing multiscale modeling concerning the balance between computational costs and the accuracy of simulations regarding the resolution of modeling. This study proposes the concept of comprehensive surface complexity (CSC) to quantity the degree of complexity of ground by integrating the topographic complexity indices and landscape indices representing the land use and land cover (LULC) complexity. Focusing on the meteorological process modeling, this paper computes the CSC by constructing a multiple regression model between the accuracy of meteorological simulation and the surface complexity of topography and LULC. Regarding the five widely studied areas of China, this paper shows the distribution of CSC and analyzes the window size effect. The comparison among the study areas shows that the CSC is highest for the Chuanyu region and lowest for the Wuhan region. To investigate the application of CSC in meteorological modeling, taking the Jingjinji region for instance, we conducted Weather Research and Forecasting Model (WRF) modeling and analyzed the relationship between CSC and the mean absolute error (MAE) of the temperature at 2 meters. The results showed that the MAE is higher over the northern and southern areas and lower over the central part of the study area, which is generally positively related to the value of CSC. Thus, it is feasible to conclude that CSC is helpful to indicate meteorological modeling capacity and identify those areas where finer scale modeling is preferable.

Magnetorheological finishing of copper cylindrical roller for its improved performance in printing machine

2020 ◽  
pp. 095440892094523
Author(s):  
Manpreet Singh ◽  
Anant Kumar Singh
Keyword(s):  
Surface Roughness ◽  
Surface Hardness ◽  
Ground Surface ◽  
Surface Characteristics ◽  
Fluid Composition ◽  
Finishing Process ◽  
Finished Surface ◽  
Measuring Machine ◽  
Mr Polishing Fluid ◽  
Cylindrical Roller

The copper cylindrical roller plays an important role in the printing operation. The copper roller requires fine and uniform finishing to uniformly distribute the colours and ingot material. Fine and uniform finishing of copper cylindrical rollers get difficulty using the traditional finishing processes due to their ductility and low hardness. Therefore, to achieve this fine finishing requirement, the rotary rectangular tool core-based magnetorheological (MR) finishing process is employed. Initially, the suitable MR polishing fluid composition is selected for the effective fine finishing of the surface of the copper cylindrical rollers. Furthermore, the central composite design is used to optimize the MR finishing process parameters. The surface roughness profiles, surface texture, and reflection tests are performed on the initial ground surface and the MR finished surface of the copper roller. The surface roughness value gets reduced from 190 nm to 25 nm after 4 hrs MR finishing with the optimum parametric conditions over the copper cylindrical roller surface having a dimension of 120 mm in length and 25 mm in diameter. The present MR finishing process found effective to significantly reduce the surface roughness value and enhance the surface characteristics of the copper cylindrical rollers. The geometrical dimensions in terms of circularity and straightness are also checked on the initial ground surface and finished surface of the copper cylindrical roller using the coordinate measuring machine and waviness test. The enhancement in surface characteristics, dimensional accuracy, and surface hardness after the present MR finishing process is found to be beneficial for improving the functional performance of the copper cylindrical rollers in the printing processing machine.

Experimental Study on Ultrasonic Vibration Dressing Wheel

2010 ◽  
Vol 135 ◽  
pp. 260-264
Author(s):  
Dao Hui Xiang ◽  
Xin Tao Zhi ◽  
Guang Xi Yue ◽  
Bo Zhao ◽  
Q.T. Fan
Keyword(s):  
Surface Quality ◽  
Ultrasonic Vibration ◽  
Ground Surface ◽  
Surface Characteristics ◽  
Axial Direction ◽  
Grinding Wheel ◽  
Workpiece Surface ◽  
Surface Burn ◽  
Grinding Conditions ◽  
Strict Requirement

Excellent wheel dressing technology can ensure the ground surface quality effectively. Because precision machining has a strict requirement on the wheel dressing, the wheel dressing with ultrasonic vibration was adopted, and the device of ultrasonic vibration dressing was also designed in this paper. On the base of analysis mechanism of ultrasonic vibration dressing wheel, the grinding experiment was carried out in different dressing conditions. The surface characteristics of ultrasonic dressing wheel and the influence of different dressing parameters on the workpiece surface quality were studied. Furthermore, the optimal dressing parameters have been obtained. The experiment results indicate that the micro cutting edge of grinding wheel distribute sparsely in circumferential directional but densely in axial direction in the condition of ultrasonic dressing, and it is particular characteristic of ultrasonic dressing. When the dressing and grinding conditions are suitable, the workpiece surface roughness can be reduced, but the conditions are not arbitrary. At the same time, the workpiece surface burn can be effectively reduced, even if the larger grinding depth is used during the grinding process.

scholarly journals Significant Contribution of Temperature on AISI D2 Tool Steel Ground Surface Characteristics and Integrities

2021 ◽  
Author(s):  
Brahim Ben Fathallah ◽  
Mohamed Rawen
Keyword(s):  
Tool Steel ◽  
Ground Surface ◽  
Surface Characteristics ◽  
Surface Damage ◽  
Surface Characteristic ◽  
Cooling Mode ◽  
Aisi D2 ◽  
Workpiece Interaction ◽  
Aisi D2 Tool Steel ◽  
Main Factor

Abstract The Controlled grinding is governed by the maximum surface temperature in the wheel-workpiece interaction. In this study, we demonstrate that temperature is the significant controller on the surface characteristic grinding, the surface integrity, the productivity and the fatigue life. Moreover, high temperature generated in abrasive processes is the main factor responsible on ground surface damage and its impact on the induced consequences in grinding of AISI D2 tool steel. The combined effects of abrasive type, cooling mode according to the cutting depth, on the temperature and residual stress distribution were highlighted by exploiting FEM. Obtained numerical results were validated with the experimental ones.

scholarly journals Effect of Surface Properties on the Fatigue Life of Manufactured Parts: Experimental Analysis and Multi-Axial Criteria

2014 ◽  
Vol 996 ◽  
pp. 715-721 ◽  
Author(s):  
Habib Sidhom ◽  
Naoufel Ben Moussa ◽  
Brahim Ben Fathallah ◽  
Naziha Sidhom ◽  
Chedly Braham
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Fatigue Strength ◽  
Work Hardening ◽  
Numerical Procedure ◽  
Ground Surface ◽  
Surface Characteristics ◽  
Fatigue Strength Improvement ◽  
Aisi D2 ◽  
Effect Of Surface

The effects of machined and treated surface characteristics on the fatigue strength were analyzed on the basis of experimental results related to AISI D2 ground surface and AA 5083-H111 hammered surface. The fatigue strength improvement resulting from controlled grinding and mechanical surface treatment was discussed on the basis of the beneficial effect of the work hardening and the stabilized residual stress. A numerical procedure using F.E.M for calculating residual stress and work hardening evolution under cyclic loading has been developed. The validation of the numerical procedure was carried out by comparing the calculated residual stress profiles to those resulted from XRD measurements. The multi-axial criterion accounting for the work hardening and the residual stress was used to predict the fatigue life of notched samples.

The Surface Heat Balance in Simulations of Permafrost Behavior

1979 ◽  
Vol 101 (4) ◽  
pp. 240-250 ◽  
Author(s):  
T. W. Miller
Keyword(s):  
Heat Balance ◽  
Thermal Protection ◽  
Ground Surface ◽  
Surface Characteristics ◽  
Climatic Conditions ◽  
Surface Heat ◽  
Transfer Program ◽  
Thermal Protection Systems ◽  
Protection Systems ◽  
Soil Thermal Properties

This paper presents a surface heat balance simulator that models the complex heat-exchange mechanisms (e.g., radiation, convection) that govern the amount of heat flowing through the ground surface. It can be used integrally with a 2-D Permafrost Heat Transfer Program [6] to implicitly calculate ground surface temperatures based on climatic conditions, surface characteristics, and soil thermal properties. Thus it provides a rational means of predicting disturbed permafrost temperatures and of designing thermal protection systems to minimize thermal disturbances. The power of the surface simulator method is demonstrated by investigating thermal disturbances and various permafrost protection schemes for both arctic and subarctic conditions, and these demonstrations show some unique differences in permafrost thermal behavior in these two regimes.

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