Loading [MathJax]/jax/output/CommonHTML/fonts/TeX/fontdata.js
  • Title/Summary/Keyword: surface roughness model

Search Result 493, Processing Time 0.024 seconds

Dynamic Response Analysis of AGT Vehicle Considering Surface Roughness of Railway (노면 요철을 고려한 AGT 차량의 동적 응답 해석)

  • Song, Jae-Pil;Kim, Chul-Woo;Kim, Ki-Bong
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.12 no.12
    • /
    • pp.986-993
    • /
    • 2002
  • The equations of motion for an automated guide-way transit(AGT) system running on a path with roughness have been derived to investigate dynamic responses and wheel loads of moving vehicles of the AGT system. A vehicle of the AGT system is idealized as three-dimensional model with 11 degree-of-freedom. The computer program is developed to solve the dynamic equations, and anlatical results are verified by comparing the results with experimental oness. Parametric studies are carried out to investigate the dynamic responses of an AGT vehicle according to vehicle speeds, surface roughness, damping and stiffness of suspension systems. The parametric study demonstrates that amplitudes of dynamic responses and the wheel loads have a tendency to increase according to travel speeds, the stiffness of suspension system and surface roughness. On the other hand. those amplitudes tend to decrease according to increase of damping of the suspension system.

자유곡면 볼엔드 밀링공정에서 CUSP PATTERN 조정

  • 심충건;양민양
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 2001.10a
    • /
    • pp.106-110
    • /
    • 2001
  • The ball-end milling process is widely used in the die/mold industries, and it is very suitable for the machining of free-form surfaces. However, this process is inherently inefficient process to compared with the end-milling or face milling process, since it relays upon the machining at the cutter/surface contact point. The machined part is the result of continuous point-to-point machining on the free-form surface. And cusps (or scallops) remain at the machined part along the cutter paths and they give the geometrical roughness of the workpiece. Thus, for the good geometrical roughness of the workpiece, it is required very tightly spaced cutter paths in this ball-endmilling process. However, with the tight cutter paths, the geometrical roughness of the workpiece is not regular on the workpiece since the cusp height is variable in the previously developed ISO-parametric or Cartesian machining methods. This paper suggests a method of tool path generation which makes the geometrical roughness of workpiece be constant through the machined surface. In this method, Ferguson Surface design Model is used and cusp height is derived from the instantaneous curvatures. And, to have constant cusp height, an increment of parameter u or v is estimated along the reference cutter path. In ball-end milling experiments, the cusp pattern was examined, and it was proved that the geometrical roughness could be regular by suggested tool path generation method.

Effect of Base Roughness of Footing on Settlement Characteristics of Footing (기초저면의 조도가 기초의 침하 특성에 미치는 영향)

  • Yoo, Nam-Jae;Kim, Young-Gil;Park, Byung-Soo
    • Journal of Industrial Technology
    • /
    • v.12
    • /
    • pp.15-23
    • /
    • 1992
  • This research is to investigate the effect of base roughness of footing on characteristics of load-settlement curve. Parametric experiments of small scaled model test were performed with changing the properties of base roughness of model footing; Gluing the vinyl, aluminum, sand paper, sand beneath the model footing surface. The width of model footing and relative density of soil foundation were also changed to investigate their effects on settlement characteristics of footing. The ultimate bearing capacity as well as the initial slope of load-settlement curve obtained from test results were compared with those from limit equilibrium methods proposed by Terzaghi, Hansen and Meyerhof. From test results, it was confirmed that the base roughness affected the failure mechanisms of showing different shapes of slip lines formed beneath the footing.

  • PDF

MONO-MATERIAL PRSSURE-CONDUCTIVE RUBBER SENSOR WITH TEMPERATURE SENSITIVITY FOR REALIZING ARTIFICIAL SKIN SENSING

  • Yuji, Jun-ichiro;Shida, Katsunori
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1997.10a
    • /
    • pp.1314-1317
    • /
    • 1997
  • For realizing artificial skin sensing as a final goal, a mono-material pressure-conductive rubber sensor which is also sensitive for temperature is described. Firstly, discimination of the hardness and the thermal property of material using a proposed sensor is presented. Furthermore, a tactile sensor constints of four pressure-conductive rubber sensor to discriminate surface model which imitaties the surface roughness of material is proposed.

  • PDF

Turbulent Fluid Flow and Heat Transfer in Concentric Annuli with Square-Ribbed Surface Roughness (사각돌출형 표면거칠기가 있는 이중동심원관 내의 난류유동과 열전달)

  • 안수환;이윤표;김경천
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.17 no.5
    • /
    • pp.1294-1303
    • /
    • 1993
  • The fully developed turbulent momentum and heat transfer induced by the square-ribed roughness elements on the inner wall surface in concentric annuli is studied analytically based on a modified turbulence model. The analytical results of the fluid flow is verified by experiment. The resulting momentum and heat transfer are discussed in terms of various parameters, such as the radius ratio, the relative roughness, the roughness density, fluid Reynolds number and for heat transfer, fluid Prandtl number. The study demonstrates that certain artificial roughness elements may be used to enhance heat transfer rates with advantages from the overall efficiency point of view.

Retrieval of surface parameters in tidal flats using radar backscattering model and multi-frequency SAR data

  • Choe, Byung-Hun;Kim, Duk-Jin
    • Korean Journal of Remote Sensing
    • /
    • v.27 no.3
    • /
    • pp.225-234
    • /
    • 2011
  • This study proposes an inversion algorithm to extract the surface parameters, such as surface roughness and soil moisture contents, using multi-frequency SAR data. The study areas include the tidal flats of Jebu Island and the reclaimed lands of Hwaong district on the western coasts of the Korean peninsula. SAR data of three frequencies were accordingly calibrated to provide precise backscattering coefficients through absolute radiometric calibration. The root mean square (RMS) height and the correlation length, which can describe the surface roughness, were extracted from the backscattering coefficients using the inversion of the Integral Equation Method (IEM). The IEM model was appropriately modified to accommodate the environmental conditions of tidal flats. Volumetric soil moisture was also simultaneously extracted from the dielectric constant using the empirical model, which define the relations between volumetric soil moistures and dielectric constants. The results obtained from the proposed algorithm were verified with the in-situ measurements, and we confirmed that multi-frequency SAR observations combined with the surface scattering model for tidal flats can be used to quantitatively retrieve the geophysical surface parameters in tidal flats.

Measurement and Analysis of Light Scattering of Au Pads on PCB Surface to Extract Scattering Parameters (인쇄회로기판용 Au 패드의 산란 특성 측정 및 분석에 의한 산란 인자 추출)

  • Ko, Nak-Hoon;Park, Dae-Seo;Kim, Young-Seok;O, Beom-Hoan;Park, Se-Geun;Lee, El-Hang;Lee, Seung-Gol;Choi, Tae-Il
    • Korean Journal of Optics and Photonics
    • /
    • v.20 no.2
    • /
    • pp.134-140
    • /
    • 2009
  • In this study, the influence of surface roughness on light scattering from Au pads on a PCB surface was investigated. Angular distributions of light scattered from Au pads with different surface roughness were measured for several incident angles. Diffusely-scattered light could be separated by using the fact that the amount of specularly-scattered light was directly related to surface roughness. The separated diffuse term was curve-fitted with a physics-based model, and then the related scattering parameters were extracted and compared with measured parameters.

Virtualized CNC Milling Machine (가상 CNC밀링머신)

  • Baek, Dae-Kyun;Oh, Myung-Seok
    • Journal of the Korean Society of Industry Convergence
    • /
    • v.4 no.4
    • /
    • pp.365-369
    • /
    • 2001
  • This paper presented a new model of virtualized CNC milling machine. The model verifies the over cut, the under cut and the surface roughness using NC file generated from CAM and cutting condition. The model uses Z-map model to verify workpiece. In this paper, the model used the velocities of x, y and z direction and obtained a center point of a hall end mill for modeling Z-map of workpiece. To investigate the performance of the model, simulation study was carried out. As the results, the model gave geometry accuracy of workpiece, the surface roughness and the chip loads in finish cutting that can predict tool chipping. The virtualized CNC machine can he used a flat end mill, a ball end mill and a rounded end mill.

  • PDF

The Performance Improvement of the Aspheric Form Accuracy by Compensation Machining Program (보정 가공 프로그램을 활용한 비구면 형상정밀도 향상에 관한 연구)

  • Park, Yo-Chang;Yang, Sun-Choel;Kim, Geon-Hee;Lee, Young-Ho
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.4 no.2
    • /
    • pp.10-15
    • /
    • 2005
  • For the development of compensation machining program, ultra precision grinding used in ultra precision machine and corrective machining was studied. We explored a new rough grinding technique on optical material such as zerodur. The facility used is a polishing machine with a custom grinding module and a range of diamond resin bond wheel. Surface roughness and form accuracy are measured by surface measurement equipment(Form Talysurf series2). Our compensation machining program has complied with a target of producing surface roughness better than 0.05μm Ra and form accuracy of around 0.05μm Rt and has been unveiled as a work-hour model.

  • PDF

A Study on the Ink Transfer Using the Roughness and Substrate Energy of Substrate in Roll to Roll Printing Systems (롤투롤 인쇄 시스템에서의 기판 소재의 거칠기와 표면에너지를 이용한 잉크 전이에 대한 연구)

  • Shin, Kee-Hyun;Kim, Ho-Joon
    • Journal of the Semiconductor & Display Technology
    • /
    • v.9 no.2
    • /
    • pp.103-109
    • /
    • 2010
  • An ink transfer is modeled and experimentally verified using roll-to-roll electric direct gravure printing process. The ink transfer model based on the physical mechanism for the maximum ink transfer rate is proposed, and experimented by the electric printing machine in FDRC for the relations of the maximum ink transfer rates to the printing pressure, the operating speed, the operating tension, the surface roughness of substrates, and the contact angle between substrate and silver ink. The free ink split coefficient and immobilized ink under the maximum ink transfer rate are calculated by the physical parameter in a printing process and contact angle between substrates and ink. Numerical simulations and experimental studies were carried out to verify performances of the proposed ink transfer model. Results showed that the proposed ink transfer model was effective for the prediction of the amount of transferred ink to the substrate in a direct gravure printing systems.