• 제목/요약/키워드: Surface roughness($R_a$)

검색결과 311건 처리시간 0.027초

선반작업(旋盤作業)에서의 FFT Analyzer에 의한 표면(表面)거칠기 해석(解析) (Analysis of Surface Roughness by FFT Analyzer in Turning Operation)

  • 김경연;최은순
    • 비파괴검사학회지
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    • 제12권3호
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    • pp.12-19
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    • 1992
  • This paper shows that the identified and unidentified components of surface roughness in NC turning lathe which can not be analyzed in time domain such as $R_{max},\;R_a$ can be isolated in frequency domain by FFT analyzer. By interfacing FFT analyzer with stylus surface roughness instrument, surface roughness on change of working condition, especially tool feed, such as 0.1, 0.15, 0.2, 0.25, 0.3(mm/rev) can be analyzed in frequency domain as follows. 1. By frequency analysis of surface roughness profile, the basic wave length of surface roughness can be obtained to isolate the identified and unidentified components of surface roughness. 2. With increase of tool feed, the unidentified components of surface roughness increase. 3. Since $R_{max}$, which can be obtained by stylus surface roughness is proportion to the output voltage of FFT analyzer, FFT analyzer also can be used to measure surface roughness in time domain such $R_a,\;R_{max}$.

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AE 신호를 이용한 연삭 가공물의 표면 거칠기 예측 (Estimation of the Ground Surface Roughness Applied by Acoustic Emission Signal)

  • 곽재섭;송지복
    • 한국정밀공학회지
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    • 제17권4호
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    • pp.240-246
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    • 2000
  • An in-process estimation of the ground surface roughness is a bottle-neck and an essential field in conventional grinding operation. We defined the dimensionless average roughness factor (D.A.R.F) that exhibits a roughness characteristics of ground surface. The D.A.R.F was composed easily of the absolute average and the standard deviation values which were the analytic parameters of the acoustic emission (AE) signal generated during the machining process. The theoretical equation between the surface roughness and the D.A.R.F has been derived from the linear regressive analysis and verified its availability through the experimentation on the surface grinding machine.

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AE 신호에 의한 연삭가공 표면거칠기 검출 (Extraction of the Surface Roughness in Grinding Operation by Acoustic Emission Signal)

  • 정성원
    • 한국산업융합학회 논문집
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    • 제2권2호
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    • pp.147-153
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    • 1999
  • An in-process extraction method of the ground surface roughness is a bottle-neck and essential field in conventional machining process. We define the D.A.R.F(Dimensionless Average Roughness Factor) that has a roughness characteristic of ground surface. D.A.R.F include the absolute average and the standard deviation values which are the analytic parameters of the AE(Acoustic Emission) signal generated during the grinding operation. The theoretical equation between the surface roughness and the D.A.R.F has been derived from the linear regressive analysis and verified its availability through the experimentation on the surface grinding machine.

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Quantification of Surface Topography Using Digital Image Analysis

  • Lee, Seok-Won
    • 한국지반공학회논문집
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    • 제15권3호
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    • pp.131-149
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    • 1999
  • 여러 연구들을 통하여 표면 거칠음 정도가 접촉면 전단력에 매우 중요함이 밝혀졌으며, 따라서 그 역할을 충분히 이해하기 위해서는 표면 거칠음 정도가 정확히 정량화 되어야 한다. 이 연구에서는 표면 형상을 정량화하기 위하여 일반적으로 사용되는 표면 거칠기 매개변수와 측정방법에 대하여 여러 참고문헌들을 검토하였다. 이것을 바탕으로 Normalized Roughness Parameter, $R_n$ (Uesugi and Kishida, 1986), Profile Roughness Parameter, $R_L$, 그리고 Surface Roughness Parameter, $R_n$(Dove and Frost, 1996)가 적합한 표면 거칠기 매개변수로 선택되었으며, 디지털 이미지 분석 시스템을 이용한 Optical Profile Microscopy(OPM) 방법을 표면 거칠음 측정방법으로 선택하였다 이 실험장비를 이용하여 일반적으로 사용되는 지오멤브레인의 표면과 표면 패턴을 대표하는, 표면이 매끄러운 것과 3가지 종류의 돌기형 HDPE 지오멤브레인을 사용하여, 전단 시험에 사용되지 않았던 지오멤브레인과 전단시험후의 지오멤브레인에 대한 표면 거칠음 정도의 정량화 작업을 수행하였다. 그 결과, $R_L과\; R_S$값은 이 연구에 사용된 지오멤브레인의 거칠음 정도를 충분한 측정범위로 표현할 수 있는 매개변수로 밝혀졌으나, $R_n$값은 충분히 표면 거칠음 정도의 차이를 표현하기에는 부족하게 매우 좁은 변화 범위를 나타내었다. 이 연구는 접촉면에서 표면 거칠음 정도가 접촉면 전단력에 미치는 영향을 조사하고자 우선적으로 표면 거칠음 정도의 정량화 작업을 연구한 것이다.

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엔드밀 가공면의 표면거칠기 모델 (Surface roughness model of end-milling surface)

  • 진도훈;김종도;윤문철
    • 한국기계가공학회지
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    • 제12권2호
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    • pp.68-74
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    • 2013
  • In this paper, an average surface roughness, $R_a$, was measured by optical measurement and its mathematical model according to spindle speed and feedrate was obtained by least square method. Also, its result is compared and investigated with real measured average surface roughness. The optical measurement of surface roughness is performed by CLSM(confocal laser scanning microscope) and the captured HEI(height encoded image) data is used as an original data for the generation of average surface roughness and its mathematical plane or contour surface of surface roughness. Using this polynomial model with two independent variables, the behavior of an average surface roughness is investigated and analyzed with an experimental modeling of least square algorithm. And it can be used for the prediction of $R_a$ in different condition of machining.

가공의 진전에 따른 표면의 프랙탈 차원 해석 (Fractal dimension analysis of machined surface according to machining progress)

  • 최임수;이기용;이득우;김정석
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1995년도 추계학술대회 논문집
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    • pp.251-254
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    • 1995
  • The quality and functionality of machined products is determined by surface finish. The surface roughness is characterized by roughness parameters such as R $_{a}$ and R $_{max}$. While such parameters are useful to define the quality of surface, they are nor sufficiently descriptive characteristics of surface. The fractal dimension which can describe characteristics od surface roughness than conventional roughness parameters has been applied. In this work, Relation between fractal dimension and surface roughness will be examined as a means of characterizing surface roughness.s.s.

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지르코니아 세라믹 연삭시 표면조도와 굽힘강도에 관한 연구 (A Study on the Surface Roughness & Bending Strength for Zirconia Ceramic Grinding)

  • 하상백;최환;이종찬
    • 한국정밀공학회지
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    • 제17권5호
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    • pp.131-136
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    • 2000
  • This paper is concerned with the surface roughness and the bending strength of ground workpiece in ZrO2 ceramic grinding. Surface roughness was measured with surface tracer and bending strength value was obtained by three-point bending test on machining center using tool dynamometer. Grinding experiments were carried out to examine the effects of grinding conditions including diamond mesh size, table speed, and depth of cut on ground surface roughness. The correlation between surface roughness and bending strength was also inspected. The experimental results indicate that the rougher surface is produced as the mesh size of diamond wheel is reduced and table speed is increased, but surface roughness is not affected by depth of cut. The values of bending strength decrease as the values of Ra, Rmax and Ku increase.

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질코니아 세라믹 연삭시 표면조도와 굽힘강도에 관한 연구 (A Study on the Surface Roughness & Bending Strength for Zirconia Ceramic Grinding)

  • 하상백
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2000년도 춘계학술대회논문집 - 한국공작기계학회
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    • pp.465-470
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    • 2000
  • This paper is concerned with the surface roughness and the bending strength of ground workpiece in ZrO2 ceramic grinding. Surface roughness was measured with surface tracer and bending strength value was obtained by three-point bending test on machining center using tool dynamometer. Grinding experiments were carried out to examine the effects of grinding conditions including diamond mesh size, table speed, and depth of cut on ground surface roughness. The correlation between surface roughness and bending strength was also inspected. The experimental results indicate that the rougher surface was produced as the mesh size of diamond wheel is reduced and table speed is increased, but surface roughness is not affected by depth of cut. The values of bending strength decrease as the values of Ra, Rmax and Ku increase.

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수종 임플랜트의 표면 거칠기와 초기안정성에 관한 연구 (A Study on the Surface Roughness and Initial Stability of Various Dental Implants)

  • 조동훈;임주환
    • 구강회복응용과학지
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    • 제16권3호
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    • pp.197-210
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    • 2000
  • Surface roughness is one of implant surface topography and it's found that surface roughness characterizations, such as surface energy, oxide layer thickness and its chemical composition, are closely correlated if the roughness is changed. Several studies showed the importance of analyzing surface structure so the surface structure of thread implant was analyzed to measure the implant quality exactly. In this study, surface roughness of 4 implants - MK $II^{(R)}$(Nobel Biocare), $RBM^{(R)}$(Life-Core, USA), $Osseotite^{(R)}$(3i, USA), $TPS^{(R)}$(Life-Core, USA) - were measured using $Accura^{(R)}$ and 40 implants were installed into 4 sets of ten bovine ribs based on the parameters from the measurements. From this test, the following conclusions for the initial stability were drawn by measuring and comparing RFA, Periotest Value (PTV), Removal Torgue Value (RTV). 1. $R_a$ value in surface roughness measurement was increasing by the order of $MKII^{(R)}$, $Osseotite^{(R)}$, $RBM^{(R)}$, $TPS^{(R)}$ and $R_q$ value was the same order. 2. $R_q$ value in each section was observed to increase by the order of $MKII^{(R)}$, $Osseotite^{(R)}$, $RBM^{(R)}$, $TPS^{(R)}$ in top and $MKII^{(R)}$, $RBM^{(R)}$, $Osseotite^{(R)}$, $TPS^{(R)}$ in mid-section but the value of $MKII^{(R)}$ bottom was the lowest, followed by $Osseotite^{(R)}$, $RBM^{(R)}$ and $TPS^{(R)}$. 3. RFA increased by the order of $RBM^{(R)}$(7042Hz), $MKII^{(R)}$(7047Hz), $Osseotite^{(R)}$(7076Hz), $TPS^{(R)}$(7168Hz) and there was no significance between each group. 4. PTV was increasing by the order of $MKII^{(R)}$(-1.62), $TPS^{(R)}$(-1.92), $Osseotite^{(R)}$ & $RBM^{(R)}$(-2.08) and there was no significance, either. 5. Removal torque in RTV measurement showed the increasing order of $MKII^{(R)}(5.31kgf{\cdot}cm)$, $Oeeotite^{(R)}(5.71kgf{\cdot}cm)$, $TPS^{(R)}(5.92kgf{\cdot}cm)$ and $RBM^{(R)}(7.24kgf{\cdot}cm)$ and there was no significance among groups. Above observations explains that surface roughness does not make any impact on the initial stability of implants installation.

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평면연삭시 AE 신호에 의한 표면거칠기 예측 (An Estimation of Surface Roughness from the AE Signal in Surface Grinding)

  • 송지복;이재경;곽재섭;이종렬
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1996년도 추계학술대회 논문집
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    • pp.115-119
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    • 1996
  • An estimation of surface roughness value is a very important and difficult issue in grinding process. The definition of the D.A.R.F(Dimensionless Average Roughness Factor) has been made including the absolute average and tile standard deviation that are the parameters of the AE(Acoustic Emission) sign. The theoretical equation of the surface roughness applying the D.A.R.F has been derived from the regressive analysis and specified with respect to the availability through the experimental approach on the machine.

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