• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.22 no.10
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• pp.974-984
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• 2012

This research introduces a new method to attenuate flip-over vibration generation in the flat blade windshield wiper by adjusting the contact pressure between the windshield glass and the blade. The knocking force in the flip-over action of the blade is decreased by inducing gradual tilting-over along the rubber strip of the blade. This gradual tilting-over is induced by introducing a non-uniform contact pressure distribution between the blade and windshield glass. The contact pressure distribution is adjusted by controlling the unloaded profile of the body spring in the blade using a procedure proposed in a previous study. Two blades, one blade designed to generate a uniform pressure distribution and the other designed to generate non-uniform pressure distribution, are developed using the procedure. Contact pressure distributions of the developed blades are measured using a special device and compared with the intended distributions confirming the similarities between the two groups. Vertical and lateral vibrations of the two blades are measured under realistic operating condition simulated by a wiper test rig. The vertical vibrations of the blade with non-uniform contact pressure are substantially smaller than corresponding vibrations of the blade with uniform contact pressure over the entire rubber strip.

• Transactions of the Korean Society of Automotive Engineers
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• v.23 no.3
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• pp.292-298
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• 2015

A wiper is a safety device removing rain and debris from windshield and ensuring visibility of drivers. If contact pressure distribution between rubber of the blade and the windshield is unbalanced, unwanted noise, vibration, and abrasion of the blade can occur and sometimes fatal accidents could occur. To improve the safety of the wiper, there have been many researches on the contact pressure analysis of the wiper, but the analysis results were not converged or require much computational time due to material nonlinearity of the rubber and contact conditions between the blade rubber and the windshield. In this research, a simple model with 1D beam and 2D shell elements was used for the contact pressure analysis instead of the 3D blade model. The simplified model saved computational time of the analysis and resolved convergence problems. The accuracy of the analysis results was verified by comparing them with experimental results for different rail spring curvatures.

• Elastomers and Composites
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• v.58 no.4
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• pp.179-190
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• 2023

The effect of the particle size and silica structure on the wear behavior of Silica/Styrene-Butadiene Rubber (SBR) compounds was investigated using a blade-type abrader and the findings were compared with those obtained with an Akron abrader. The compensated characteristic parameter (Ψ_c), which was the contributory factor of the combined effect of the particle size and filler structure, was introduced. This parameter was found to exhibit a linear relationship with the Young's modulus. The Young's modulus correlated more with Ψ_c than the uncompensated characteristic parameter (Ψ) modeled for carbon black. The wear rate and volume loss measured using a blade-type abrader and Akron abrader were respectively observed to be inversely proportional to Ψ_c, that is, the wear resistance of Silica/SBR compound improved as the particle size became smaller and the silica structure became intricate. The coefficient of determination (R²) obtained from the linear relationship between Ψ_c and wear rate was higher than those between Ψ_c and volume loss for the Silica/SBR compound. Thus, the blade-type abrader exhibited high potential to be used for accurately evaluating the effect of particle size and structural properties of silica on the wear behavior of SBR compounds.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.2
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• pp.105-115
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• 2008

Statement of problem: Proper finishing and polishing enhance both the esthetics and the longevity of restored teeth. Blade finishing technique would be suited for smoothing and finishing. Evaluation of this technique are necessary. Purpose: The purpose of this study was to evaluate the blade finishing and polishing procedures on the surface profile and roughness of ormocer-based composite resin and nanohybrid composite resin. Material and methods: The material included a ormocer-based composite resin ($Admira^{(R)}$ & $Admira^{(R)}$ Flow); a nanohybrid composite resin ($Grandio^{(R)}$ & $Grandio^{(R)}$ Flow). One hundred forty specimens of each group were prepared using a mylar strip and randomly divied into blade finishing and rubber polishing groups (n=10). The average surface roughness (Ra) in micrometers was measured and the surface profile was examined by scanning electron microscopy (SEM) (Magnification ${\times}$ 200). The data were analyzed by Mann-Whitney Test at 0.05 significance level. Conclusion: The results of this study indicated that the mylar strip produced the smoothest surface on all materials and among the finishing-polishing methods was not significanct difference (P>0.05). Ormocer-based flowable composite resin performedthe lowest variability in initial surface roughness among the tested materials.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.5
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• pp.784-789
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• 2012

Ultrasonic Cutting which uses a tuned blade resonant in a longitudinal mode, has been used to cut a range of materials from confectionery, baked products and frozen foods, to wood, bone, foams and composites. The Blade design typically uses finite element analysis, and it could be predicted vibration mode, gain and amplitude uniformity of the blade tip at resonant frequency. In this paper, FEA used to predict the vibration characteristic of the blade, and then the results were verified by analysis system of resonant frequency using the processed blade. The crack of the blade which is predicted from FEA was compared with the crack occurred by cutting experiment of rubber materials using the processed blade.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.901-902
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• 2012

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.2
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• pp.55-62
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• 2013

An analytical procedure to determine a proper profile of the spring rail that generates intended contact pressure distribution in the flat wiper blade is introduced. The flat wiper blade is one piece blade and subjected to pressing force at a center point. In this type of blade, contact pressure distribution in the tip of rubber strip is determined by the pressing force, the initial profile of the blade before contact and bending stiffness of the blade. Experimentally obtained bending stiffness of the blade assembly is almost identical to that of the spring rail. Principle of reciprocity has been used to define the initial profile of spring rail from the deformed profile that is assumed to be identical to the windshield glass profile. The procedure has been verified experimentally by measuring the contact pressure of the blade assembled with the spring rail designed by the procedure proposed here. Measured contact pressure distributions of the blades show good agreements with intended distributions over the entire blade span. Consequently, it can be concluded that proposed procedure has relatively good accuracy in developing the spring rail for flat blade having a specific contact pressure distribution.

• The Journal of the Korean dental association
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• v.25 no.12 s.223
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• pp.1145-1156
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• 1987

The purpose of this experimental study was to analyze the stress distribution from fixed partial dentures to the surrounding structures. This study was carried out on the experimental bridges with K-L blade, F.D.B.I.-11 type, F.D.B.I.-21 type, shape-memory metal blade and two-Apacerams as posterior abutment. The stress patterns and fringes were observed through the circular transmission polariscope. The results of this study were obtained as follows: 1. The stress was more concentrated to the roots apex than the implants. 2. In all blade implants, the stress was more concentrated to the distal side than the mesial side. 3. F.D.B.I.-11 type was more stress concentrated than the 21 type. 4. Shape-memory metal blade was the most effective for stress distribution. 5. Apacerams were more stress concentrated than the blde types and in the model of Apaceram with rubber-ring, anterior root was tipped distally.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.3
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• pp.51-57
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• 2006

The contact pressure distribution between a rubber wiper blade and a glass windshield is a major factor for wiping performance. A modeling and simulation method has been developed to forecast the contact pressure distribution on a wiper blade. For modeling multi-body dynamics of an wiper linkage system and flexible nature of wiper blade, ADAMS and ADAMS/flex are employed. A simulation study has been also conducted to obtain contact pressure distribution. Comparison between simulation and measurement is provided to ensure fidelity of the model and the simulation method.

• Elastomers and Composites
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• v.54 no.4
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• pp.313-320
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• 2019

A typical wear pattern was reported to resemble the fatigue crack growth behavior considering its mechanism, especially for amorphous rubbers such as styrene-butadiene rubber (SBR). In this study, the wear and crack growth rates were correlated using two separate experiments for carbon black and silica-reinforced selected rubber compounds. The wear rate was determined using a blade-type abrasion tester, where the frictional energy input during wearing was measured. The crack propagation rate was determined under different tearing energy inputs using a home-made fatigue tester, with a pure-shear test specimen containing pre-cracks. The rates of abrasion and crack propagation were plotted on a log-log scale as a function of frictional and tearing energies, respectively. Reasonable agreement was observed, indicating that the major mechanism of the abrasion pattern involved repeated crack propagation.