• Title/Summary/Keyword: surface program

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Turbine Blade Surface Modeling of Point Data Fitting (측정 데이타를 이용한 터어빈 블레이드의 곡면설계)

  • Ryu, Gap-Sang;Park, Sam-Jin
    • 한국기계연구소 소보
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    • s.19
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    • pp.163-169
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    • 1989
  • Many computer programs are being developed to aid the design of physical models. These efforts highlight the importance of computer model of three dimensional object. In this paper a CAD application program is introduced which can be implemented to modeling some part that composed with 3 types of surface form ; free form surface, fillt surface, surface of revolution, and a geometry description language which can represent a shape efficiently is preseneted.

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The effect of repeated surface treatment of zirconia on its bond strength to resin cement

  • Maciel, Lucas Campagnaro;Amaral, Marina;Queiroz, Daher Antonio;Baroudi, Kusai;Silva-Concilio, Lais Regiane
    • The Journal of Advanced Prosthodontics
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    • v.12 no.5
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    • pp.291-298
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    • 2020
  • PURPOSE. The aim of this study is to evaluate the influence of repeated surface treatments on wettability and surface roughness for zirconia surface and bond strength of zirconia-based ceramics to resin cement. MATERIALS AND METHODS. Seventy blocks (10 × 10 × 3 mm) of zirconia-based ceramics were fabricated and divided into two groups according to the surface treatments: (A) 110 ㎛ Al2O3 airborne-particle abrasion and (R) 110 ㎛ silica modified Al2O3 airborne-particle abrasion. At stage 2, each group was subdivided into 5 groups according to the surface retreatments: (a) 110 ㎛ Al2O3 airborne-particle abrasion, (r) 110 ㎛ silica modified Al2O3 airborne-particle abrasion, (D) diamond bur, (Da) diamond bur + 110 ㎛ Al2O3 airborne-particle abrasion, and (Dr) diamond bur + 110 ㎛ silica modified Al2O3 airborne-particle abrasion. Cylinders of self-adhesive resin cement were cemented onto each treated ceramic surface and subjected to micro-shear bond strength test. Additional specimens were prepared for roughness and wettability analyses. The data were subjected to t-test and One-way ANOVA followed by Tukey's post hoc test (α=.05). RESULTS. At stage 1, group R presented higher bond strength values than group A (P=.000). There was a statistically significant increase of bond strength at stage 2 for group A (P=.003). The diamond bur influenced the surface roughness, increasing the values (P=.023). Group R provided better wettability. Regardless of the applied surface treatment, most of failures were adhesive. CONCLUSION. The combination of application and reapplication of Rocatec Plus showed the best results of bond strength. Surface retreatment and recementation might be an indicated clinical strategy.

[ $C^{\ast}$ ]-integral Based Life Assessment of High Temperature Pipes ($C^{\ast}$-적분에 기초한 고온배관 수명평가)

  • Lee Hyungyil
    • Journal of the Korean Institute of Gas
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    • v.4 no.4 s.12
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    • pp.25-33
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    • 2000
  • In recent years, the subject of remaining life assessment has drawn considerable attention in power plants, where various structural components typically operate at high temperature and pressure. Thus a life prediction methodology accounting for high temperature creep fracture is increasingly needed for the components. Critical defects in such structures are generally found in the form of semi-elliptical surface crack, and the analysis of which is consequently an important problem in engineering fracture mechanics. On this background, we first develop an auto mesh generation program for detailed 3-D finite element analyses of axial and circumferential semi-elliptical surface cracks in a piping system. A high temperature creep fracture parameter $C^{\ast}$-integral is obtained from the finite element analyses of generated 3-D models. Post crack growth module is further appended here to calculate the amount of crack growth. Finally the remaining lives of surface cracked pipes for various analytical parameters are assessed using the developed life assessment program.

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The development of a mesh generation program using contour line data (등고선 데이터를 이용한 산악지형 유동해석 격자생성 프로그램 개발 및 그 응용)

  • Chin S. M.;Won C. S.;Hur N.
    • 한국전산유체공학회:학술대회논문집
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    • 2004.03a
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    • pp.202-207
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    • 2004
  • In the present study a mesh generation program has been developed by using DXF file. The program consists of DXF file reading and mapping algorithm, which projects the 2-D mesh point onto the triangular surface constructed by nearest three points. The present program has been tested for mesh generations for the road tunnel ventilation analysis and analysis of lava movement in mountain area.

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Stability Analysis of Anchored Slope Considering Load Transfer (하중전이를 고려한 앵커보강사면의 안정해석)

  • Kim, Nak-Kyung;Yun, Seung-Kwon;Kim, Sung-Kyu;Joo, Yong-Sun;Park, Jong-Sik
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.03a
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    • pp.1113-1124
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    • 2009
  • The limit equilibrium method and finite element method have been commonly used to assess the stability of anchored slope. However, the existing limit equilibrium methods do not consider the load transfer of anchor and, if the potential failure surface crosses the bonded zone of anchors, the anchor loads are not included in computing the factor of safety. In this paper, simplified bishop method, one among several methods based on the limit equilibrium is used to develope the Excel Sheet program and the working load of anchor along the failure surface is calculated by Flamant's formula, proposed by Morlier and Tenier(1982). Additionally, the finite element analysis of anchored slope considering the load transfer is performed in order to compare with the result from the limit equilibrium analysis and analyze the reinforced effect of anchor. From this study, new modelling method that limits the reinforcing range and considers the load transfer is proposed and Excel Sheet program is developed. The factor of safety for several cases between PC STABL and Excel Sheet program is also compared for verification of the program.

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The Correlation Between Changes of Ankle Joint Position Sense and Sway Area Through Unstable Surface Training (불안정지지면 훈련을 통한 발목관절위치감각 변화와 동요면적 변화간의 상관관계)

  • Ha, Na-Ra;Kim, Myung-Chul;Han, Seul-Ki
    • The Journal of the Korea institute of electronic communication sciences
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    • v.8 no.9
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    • pp.1383-1389
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    • 2013
  • This research was conducted to see the correlation between changes of ankle Joint Position Sense and Sway Area through Unstable Surface training. For the study, 48 healthy males and females were randomly divided into an unstable surface group(n=24) and a stable surface group(n=24). Then, they were asked to carry out the same exercise program three times a week for six weeks. The unstable surface group and stable surface group performed the exercise program on the balance exercise pad and on the hard ground, respectively. As a result, the unstable surface group displayed significantly reduced error of ankle joint position sense and sway area(p<.05). Moreover, a significant correlation between variances of ankle joint position sense and sway area was only found in the unstable surface group. In conclusion, this study demonstrated that there was a significant correlation between changes of ankle joint position sense and sway area through proprioceptive sense training on the unstable surface.

Controll over the Au@Ag Core-shell Nanoparticle 2D Patterns via Diblock Copolymer Inverse Micelle Templates and Investigation of the Surface Plasmon Based Optical Property (이중블록공중합체 역마이셀 주형을 이용한 Au@Ag 코어-쉘 나노입자 2차원 패턴 제어 및 표면 플라즈몬 기반 광학적 특성 연구)

  • Yoon, Min Ji;Kim, Jihyeon;Jang, Yoon Hee;Lee, Ji-Eun;Chung, Kyungwha;Quan, Li Na;Kim, Dong Ha
    • Journal of the Korean Chemical Society
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    • v.57 no.5
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    • pp.618-624
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    • 2013
  • We demonstrated unique inter- and intra-plasmonic coupling effects in bimetallic Au@Ag core-shell NP arrays which are regularly or randomly arranged on self-assembled block copolymer (BCP) inverse micelle monolayers. Polyvinylpyrrolidone (PVP)-stabilized Au@Ag core-shell NP arrays in regular or disordered configuration were incorporated and assembled on reconstructed PS-b-P4VP inverse micelle templates through two types of processes. The intensively enhanced LSPR coupling properties of individual and assembled Au@Ag NPs were evaluated by UV-visible spectroscopy in terms of the type of ligand stabilizer, coupling between Au and Ag, thickness of Ag shell, and type of array configuration. Finally, Au@Ag core-shell NP arrays were employed as active substrates for surface enhanced Raman spectroscopy (SERS) and a significantly enhanced signal enhancement was observed in accordance with the coupling intensity of Au@Ag NPs patterns.

Surface plasmon resonance sensor (표면 플라스몬 공명 센서의 제작)

  • Han, Won-Sik;Jung, Kyu-Jin;Lee, Sang-Won;Hong, Suk-Young;Lee, Young-Hoon;Hong, Tae-Kee
    • Analytical Science and Technology
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    • v.19 no.1
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    • pp.9-17
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    • 2006
  • The application and analysis of the interaction of various biomaterials including the concentration of biomaterials, thickness, and the ability of the detection of the analytical kinetic data of special biomaterials have been performed by SPR(surface plasmon resonance) sensor. To fabricate the scanning SPR, we designed data acquisition board and LabVIEW program for the personal computer to control the SPR sensor and collect the data from detector.

A Study on the Construction of Response Surfaces for Design Optimization (최적설계를 위한 반응표면의 생성에 관한 연구)

  • Hong, Gyeong-Jin;Jeon, Gwang-Gi;Jo, Yeong-Seok;Choe, Dong-Hun;Lee, Se-Jeong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.6 s.177
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    • pp.1408-1418
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    • 2000
  • Gradient-based optimization methods are inefficient in applications which require expensive function evaluations, and useless in applications where objective and/or constraint functions are 'noisy' due to modeling and cumulative numerical inaccuracy since gradient evaluation results cannot be reliable. Moreover, it is difficult to be integrated with commercial analysis software, and they cannot be employed when only experimental analysis results are available. In this research an optimization program based on a response surface method has been developed to overcome the aforementioned difficulties. Various methods for design of experiments and new proposed approximation models are implemented in the program. The effectiveness of the optimization program is tested on several test problems and results are discussed.