Effects of Surface Roughness on Multi-Station Mechanical Alignment Processes

2000 ◽  
Vol 123 (3) ◽  
pp. 433-444 ◽  
Author(s):  
Neville K. S. Lee ◽  
J. Y. Chen ◽  
Ajay Joneja
Keyword(s):  
Surface Roughness ◽  
Simulation Study ◽  
Manufacturing Processes ◽  
Mechanical Alignment ◽  
Theoretical Simulation ◽  
Geometric Consideration ◽  
Alignment System ◽  
The Difference

A theoretical simulation study was performed to study how surface roughness of the workpiece and datum can affect the locating precision of multiple station manufacturing processes using a mechanical alignment system. Our analysis shows that geometric consideration, a factor that has not been treated before, is extremely important for many multi-station applications. As expected, the level of alignment precision decreases when the level of surface roughness of the workpieces increases. Our analysis also shows that the effect of the sample roughness on the level of alignment precision depends heavily on the difference in the relative positions of the datum between different workstations.

scholarly journals Effect of tillage, slope, and rainfall on soil surface microtopography quantified by geostatistical and fractal indices during sheet erosion

2020 ◽  
Vol 12 (1) ◽  
pp. 232-241
Author(s):  
Na Ta ◽  
Chutian Zhang ◽  
Hongru Ding ◽  
Qingfeng Zhang
Keyword(s):  
Surface Roughness ◽  
Fractal Dimension ◽  
Soil Surface ◽  
Rainfall Events ◽  
Tillage Practices ◽  
Surface Microtopography ◽  
Artificial Rainfall ◽  
Soil Surface Roughness ◽  
The Difference ◽  
Sheet Erosion

AbstractTillage and slope will influence soil surface roughness that changes during rainfall events. This study tests this effect under controlled conditions quantified by geostatistical and fractal indices. When four commonly adopted tillage practices, namely, artificial backhoe (AB), artificial digging (AD), contour tillage (CT), and linear slope (CK), were prepared on soil surfaces at 2 × 1 × 0.5 m soil pans at 5°, 10°, or 20° slope gradients, artificial rainfall with an intensity of 60 or 90 mm h−1 was applied to it. Measurements of the difference in elevation points of the surface profiles were taken before rainfall and after rainfall events for sheet erosion. Tillage practices had a relationship with fractal indices that the surface treated with CT exhibited the biggest fractal dimension D value, followed by the surfaces AD, AB, and CK. Surfaces under a stronger rainfall tended to have a greater D value. Tillage treatments affected anisotropy differently and the surface CT had the strongest effect on anisotropy, followed by the surfaces AD, AB, and CK. A steeper surface would have less effect on anisotropy. Since the surface CT had the strongest effect on spatial variability or the weakest spatial autocorrelation, it had the smallest effect on runoff and sediment yield. Therefore, tillage CT could make a better tillage practice of conserving water and soil. Simultaneously, changes in semivariogram and fractal parameters for surface roughness were examined and evaluated. Fractal parameter – crossover length l – is more sensitive than fractal dimension D to rainfall action to describe vertical differences in soil surface roughness evolution.

Effect of Mechanical Alignment System on Assembly Accuracy

2000 ◽  
Author(s):  
Neville K. S. Lee ◽  
Grace H. Yu ◽  
Y. Zou ◽  
J. Y. Chen ◽  
Ajay Joneja
Keyword(s):  
Alignment Accuracy ◽  
Mechanical Alignment ◽  
Mechanical Assembly ◽  
Surface Waviness ◽  
Form Errors ◽  
Multi Stage ◽  
Assembly Accuracy ◽  
Alignment System ◽  
Simulation Based ◽  
Selection Of

Abstract Mechanical means of positioning are frequently used in mechanical assembly processes. However, very little attention has been paid to the selection of mechanical alignment systems (MAS) for assembly processes. Our analysis shows that if the MAS are not properly selected, the form errors as well surface waviness and roughness of the workpieces to be assembled can badly limit the level of accuracy achievable. A simulation-based methodology is described to study the alignment accuracy for multi-stage processes. Such cases are common, where fabrication operations are done on parts before they are assembled. The study shows that if the workpieces are aligned in the same orientation, using similar or identical MAS for the fabrication processes and assembly processes, then the effect of the form errors as well as surface waviness and roughness of the workpieces can be greatly suppressed.

scholarly journals Defect Detection in Striped Images Using a One-Dimensional Median Filter

2020 ◽  
Vol 10 (3) ◽  
pp. 1012
Author(s):  
Wei-Chen Lee ◽  
Pei-Ling Tai
Keyword(s):  
Image Processing ◽  
Defect Detection ◽  
Median Filter ◽  
Detection Methods ◽  
Manufacturing Processes ◽  
Image Binarization ◽  
Image Processing Algorithm ◽  
One Dimensional ◽  
Modern Manufacturing ◽  
The Difference

Defect detection is a key element of quality assurance in many modern manufacturing processes. Defect detection methods, however, often involve a great deal of time and manual work. Image processing has become widely used as a means of reducing the required detection time and effort in manufacturing. To this end, this study proposes an image-processing algorithm for detecting defects in images with striped backgrounds—defect types include scratches and stains. In order to detect defects, the proposed method first pre-processes images and rotates them to align the stripes horizontally. Then, the images are divided into two parts: blocks and intervals. For the blocks, a one-dimensional median filter is used to generate defect-free images, and the difference between the original images and the defect-free images is calculated to find defects. For the intervals, defects are identified using image binarization. Finally, the method superposes the results found in the blocks and intervals to obtain final images with all defects marked. This study evaluated the performance of the proposed algorithm using 65 synthesized images and 20 actual images. The method achieved an accuracy of 97.2% based on the correctness of the defect locations. The defects that could not be identified were those whose greyscales were very close to those of the background.

Influence of Abrasive on Planarization Grinding Based on the Cluster Magnetorheological Effect

2011 ◽  
Vol 325 ◽  
pp. 542-547
Author(s):  
Qiu Sheng Yan ◽  
Jie Wen Yan ◽  
Jia Bin Lu ◽  
Wei Qiang Gao ◽  
Min Li
Keyword(s):  
Surface Roughness ◽  
Grain Size ◽  
Optical Glass ◽  
Removal Rate ◽  
Mr Fluid ◽  
Grinding Method ◽  
Magnetorheological Effect ◽  
The Difference ◽  
Mr Effect

A new planarization grinding method based on the cluster magnetorheological (MR) effect is presented to grind optical glass in this paper. Some process experiments were conducted to reveal the influence of the species and granularity and content of the abrasive materials in the MR fluid on the machining effect, furthermore, the machining characteristic of grinded surface was studied. The results indicate that the abrasive influences definitively on machining effect of this planarization grinding method based on the cluster MR-effect. Under the certain experiment condition, with the content of the abrasive 10% and grain size 800# of SiC, best machining effect can be achieved. The difference species of abrasive results in various machining effects. As for the removal rate of K9 optical glass: abrasive CeO2 is the best, the Al2O3 is the second and the SiC is the worst. While the surface roughness: abrasive SiC is the lowest，the Al2O3 is the second and CeO2 is the highest.

Effects of Cutting Condition on Surface Roughness when Turning Untreated and Sb-Treated Al-11%Si Alloys Using PVD Coated Tools

2013 ◽  
Vol 315 ◽  
pp. 413-417 ◽  
Author(s):  
Mohsen Marani Barzani ◽  
Mohd Yusof Noordin ◽  
Ali Akhavan Farid ◽  
Saaed Farahany ◽  
Ali Davoudinejad
Keyword(s):  
Surface Roughness ◽  
Cutting Speed ◽  
Depth Of Cut ◽  
Manufacturing Processes ◽  
Cutting Condition ◽  
Dry Cutting ◽  
Fabrication Cost ◽  
Coated Tools ◽  
Experimental Trials ◽  
Cutting Speeds

Surface roughness is an important output in different manufacturing processes. Its characteristic affects directly the performance of mechanical components and the fabrication cost. In this current work, an experimental investigation was conducted to determine the effects of various cutting speeds and feed rates on surface roughness in turning the untreated and Sb-treated Al-11%Si alloys. Experimental trials carried out using PVD TIN coated inserts. Experiments accomplished under oblique dry cutting when three different cutting speeds have been used at 70, 130 and 250 m/min with feed rates of 0.05, 0.1 and 0.15 mm/rev, whereas depth of cut kept constant at 0.05 mm. The results showed that Sb-treated Al-11%Si alloys have poor surface roughness in comparison to untreated Al-11%Si alloy. The surface roughness values reduce with cutting speed increment from 70 m/min to 250 m/min. Also, the surface finish deteriorated with increase in feed rate from 0.5 mm/rev to 0.15 mm/rev.

Conversion Methods of Efficiency for Hydraulic Machinery Using Model Under Influence of Roughness

2008 ◽  
Author(s):  
Long Li ◽  
Ze Wang ◽  
Xuelin Yang ◽  
Dan Li
Keyword(s):  
Surface Roughness ◽  
Friction Coefficient ◽  
Computational Method ◽  
Hydraulic Loss ◽  
Simple Computation ◽  
Hydraulic Efficiency ◽  
Hydraulic Machinery ◽  
Computation Process ◽  
Efficiency Conversion ◽  
The Difference

The hydraulic efficiency conversion method of Moody formula based on H. Blasius friction coefficient formula for the “Hydraulically smooth zone” was analyzed. The method of model to prototype that involves the influence of the surface roughness of hydraulic machinery was advised. The conversion result was compared among the Haaland fomula, the Swamee-Jain formula, and the different proportion of hydraulic loss type. It was contrasted with the standard method. The difference of prototype efficiency is no bigger than 0.0025 in the prototype roughness 0.025mm range. The proposed computational method is provided with the same characteristics with the flowing zone, and possessed the clear physics significance, the simple computation process and the high conversion precision. It is satisfied with the efficiency conversion under the influence of the surface roughness.

Practical Dimensional Error Control and Surface Roughness Inspection in Turning

2002 ◽  
Author(s):  
M. Shiraishi ◽  
T. Yamagiwa ◽  
A. Ito
Keyword(s):  
Surface Roughness ◽  
Optical Method ◽  
Machine Tools ◽  
Error Control ◽  
Manufacturing Processes ◽  
Dimensional Error ◽  
Final Output

Monitoring of machine tools and optimization of manufacturing processes require accurate values of in process measured quantities such as dimensional error, force, and surface roughness. The measurement as workpiece is in particular important because the final output in machining is evaluated as the quality machined workpiece itself. A new hybrid sensor using pneumatic and optical method has been developed which can monitor the dimensional error and surface roughness in turning. Satisfactory results were obtained through several experiments.

A multi-scale modeling and simulation study to investigate the effect of roughness of a surface on its self-cleaning performance

2020 ◽  
Vol 5 (7) ◽  
pp. 1277-1289 ◽  
Author(s):  
Sushanta K. Sethi ◽  
Manjinder Singh ◽  
Gaurav Manik
Keyword(s):  
Surface Roughness ◽  
Modeling And Simulation ◽  
Simulation Study ◽  
Multi Scale ◽  
Cleaning Performance ◽  
Scale Modeling ◽  
Multi Scale Modeling ◽  
Self Cleaning

The importance of surface roughness on wettability is vital in developing novel techniques and materials for fabrication of self-cleaning coatings.

scholarly journals The Difference Between Set and Delivered Tidal Volume: A Lung Simulation Study

2020 ◽  
Vol Volume 13 ◽  
pp. 205-211
Author(s):  
Yoshikazu Yamaguchi ◽  
Tetsuya Miyashita ◽  
Yuko Matsuda ◽  
Makoto Sasaki ◽  
Shunsuke Takaki ◽  
...  
Keyword(s):  
Tidal Volume ◽  
Simulation Study ◽  
The Difference ◽  
Lung Simulation

Ceramic Additive Manufacturing Using VAT Photopolymerization

2018 ◽  
Author(s):  
Diptanshu ◽  
Erik Young ◽  
Chao Ma ◽  
Suleiman Obeidat ◽  
Bo Pang ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Additive Manufacturing ◽  
Thermal Processing ◽  
Biomedical Applications ◽  
Ceramic Materials ◽  
Ceramic Suspension ◽  
Alumina Particles ◽  
Compressive Testing ◽  
The Difference ◽  
Porosity Percentage

The popularity of additive manufacturing for producing porous bio-ceramics using vat photopolymerization in the recent years has gained a lot of impetus due to its high resolution and low surface roughness. In this study, a commercial vat polymerization printer (Nobel Superfine, XYZprinting) was used to create green bodies using a ceramic suspension consisting of 10 vol.% of alumina particles in a photopolymerizable resin. Four different sizes of cubical green bodies were printed out. They were subjected to thermal processing which included de-binding to get rid of the polymer and thereafter sintering for joining of the ceramic particles. The porosity percentage of the four different sizes were measured and compared. The lowest porosity was observed in the smallest cubes (5 mm). It was found to be 43.3%. There was an increase in the porosity of the sintered parts for the larger cubes (10, 15 and 20 mm). However, the difference in the porosity among these sizes was not significant and ranged from 61.5% to 65.2%. The compressive testing of the samples showed that the strength of the 5-mm cube was the maximum among all samples and the compressive strength decreased as the size of the samples increased. These ceramic materials of various densities are of great interest for biomedical applications.

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