• Title/Summary/Keyword: Inclined angle

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An Analytical Study on Inclination of Vertical Piles (연직말뚝의 경사도 오차에 관한 해석적 연구)

  • 장정욱;박춘식;최차석
    • Proceedings of the Korean Geotechical Society Conference
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    • 2003.03a
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    • pp.463-468
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    • 2003
  • This paper studied the effects of inclination of piles on pile behaviors. The following are the conclusions of this study. (1) When all the piles are inclined to a same direction, the piles reaction, maximum moment and horizontal displacement of footing increase as the angle of inclination increases. (2) When the piles of each opposite side are inclined symmetrically, the vertical reaction either increases or decreases in proportion to the angle of inclination. In this case, the vertical reaction of inclined piles decreases but the vertical reaction of non-Inclined piles increases.

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The simulation study on natural circulation operating characteristics of FNPP in inclined condition

  • Li, Ren;Xia, Genglei;Peng, Minjun;Sun, Lin
    • Nuclear Engineering and Technology
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    • v.51 no.7
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    • pp.1738-1748
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    • 2019
  • Previous research has shown that the inclined condition has an impact on the natural circulation (natural circulation) mode operation of Floating Nuclear Power Plant (FNPP) mounted on the movable marine platform. Due to its compact structure, small volume, strong maneuverability, the Integral Pressurized Water Reactor (IPWR) is adopted as marine reactor in general. The OTSGs of IPWR are symmetrically arranged in the annular region between the reactor vessel and core support barrel in this paper. Therefore, many parallel natural circulation loops are built between the core and the OTSGs primary side when the main pump is stopped. and the inclined condition would lead to discrepancies of the natural circulation drive head among the OTSGs in different locations. In addition, the flow rate and temperature nonuniform distribution of the core caused by inclined condition are coupled with the thermal hydraulics parameters maldistribution caused by OTSG group operating mode on low power operation. By means of the RELAP5 codes were modified by adding module calculating the effect of inclined, heaving and rolling condition, the simulation model of IPWR in inclined condition was built. Using the models developed, the influences on natural circulation operation by inclined angle and OTSG position, the transitions between forced circulation (forced circulation) and natural circulation and the effect on natural circulation operation by different OTSG grouping situations in inclined condition were analyzed. It was observed that a larger inclined angle results the temperature of the core outlet is too high and the OTSG superheat steam is insufficient in natural circulation mode operation. In general, the inclined angle is smaller unless the hull is destroyed seriously or the platform overturn in the ocean. In consequence, the results indicated that the IPWR in the movable marine platform in natural circulation mode operation is safety. Selecting an appropriate average temperature setting value or operating the uplifted OTSG group individually is able to reduce the influence on natural circulation flow of IPWR by inclined condition.

Influence of the Inclined Hole in Residual Stresses Measurement Using the Hole-Drilling Method (구멍뚫기법을 이용한 잔류응력 측정시 경사구멍의 영향)

  • Kim, Cheol;Yang, Won-Ho;Seok, Chang-Sung;Heo, Sung-Pil
    • Transactions of the Korean Society of Automotive Engineers
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    • v.9 no.6
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    • pp.201-206
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    • 2001
  • The hole-drilling method makes a little hole through the metal surface that has residual stress and measures the relieved stress with a strain gage. It is used widely in measuring the residual stress of surfaces. In this method, the inclined hole is one of the source of error. This paper presents a finite element analysis of influence of the inclined hole for the uniaxial residual stress field. The stress differences between measured and applied residual stress increase proportionally to inclined angle of the hole. The correction equations which easily obtain the residual stress taking account of the inclined angle and direction are derived. The measurement error of stress due to the inclined hole can be reduced to around 1% through this study.

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The Effect of Abutment Inclined Angle on the Marginal Fit of Zirconia All-ceramic Crown (지대주 경사각이 지르코니아 전부도재관의 변연적합도에 미치는 영향)

  • Lee, Seo-Yeon;Chung, In-Sung;Jeon, Byung-Wook
    • Journal of Technologic Dentistry
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    • v.38 no.3
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    • pp.111-117
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    • 2016
  • Purpose: The present study was performed to investigate the effect of abutment inclined angle on the marginal fit of zirconia all-ceramic crown. Methods: The Ti abutments with 3 different inclined angle($2^{\circ}$, $4^{\circ}$ and $6^{\circ}$) were fabricated. The zirconia copings were fabricated for each abutment by using dental CAD/CAM system. The manufactured zirconia copings were duplicated through silicone replica technique, and a replicated specimen was sectioned in the center of bucco-lingual and mesio-distal axial to measure the marginal fit by using a stereo microscope. The results were analyzed using a one-way ANOVA with SPSS 22.0 for Windows(${\alpha}=0.05$). Results: On the bucco-lingual axial, marginal fit was the RL3($41.5{\pm}3.4{\mu}m$), RL2($44.3{\pm}4.3{\mu}m$) and RL1($47.5{\pm}5.7{\mu}m$), respectively. On the mesio-distal axial, marginal fit was the RL3($41.1{\pm}3.7{\mu}m$), RL2($45.7{\pm}5.3{\mu}m$) and RL1($46.2{\pm}4.5{\mu}m$), respectively. One-way ANOVA showed statistically significant difference between groups for marginal fit(p<0.05). Conclusion: For marginal fit of the abutments inclined angle, RL3 specimen was superior. The abutment inclined angle had influence on marginal fit of the zirconia copings. The marginal fit of each group were within clinically acceptable range.

Fiber Bridging Model Considering Probability Density Function of Fiber Inclined Angle in Engineered Cementitious Composites (보강 섬유의 배향각에 대한 확률밀도함수를 고려한 ECC내의 섬유 가교 모델)

  • Kang, Cheol-Ho;Lee, Bang-Yeun;Park, Seung-Bum;Kim, Yun-Yong
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.22 no.6
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    • pp.587-596
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    • 2009
  • The fiber bridging model is the crucial factor to predict or analyze the tensile behavior of fiber reinforced cementitious composites. This paper presents the fiber bridging constitutive law considering the distribution of fiber inclined angle and the number of fibers in engineered cementitious composites. The distribution of fiber inclined angle and the number of fibers are measured and analyzed by the image processing technique. The fiber distribution are considerably different from those obtained by assuming two- or three-dimensional random distributions for the fiber inclined angle. The simulation of the uniaxial tension behavior was performed considering the distribution of fiber inclined angle and number of fibers measured by the sectional image analysis. The simulation results exhibit multiple cracking and strain hardening behavior that correspond well with test results.

Influence of Inclined Holes in Measurement of Residual Stress by the Hole Drilling Method

  • Kim, Cheol;Yang, Won-Ho;Heo, Sung-Pil
    • Journal of Mechanical Science and Technology
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    • v.15 no.12
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    • pp.1647-1654
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    • 2001
  • The hole drilling method is widely used in measuring residual stress in surfaces. In this method, the inclination of holes is one of the sources of error. This paper presents a finite element analysis of the influence of inclined holes on the uniaxial residual stress field. The error in stress has been found to increase proportionally to the correct inclined angle of the hole. The correction equations by which one may easily obtain the residual stress, taking account of the inclined angle and direction, have been derived. The error of stress due to the inclined hole has been reduced to around 1% using the correction equations.

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Inclination angle influence on noise of cavitating marine propeller

  • Bal, Sakir
    • Ocean Systems Engineering
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    • v.10 no.1
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    • pp.49-65
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    • 2020
  • In this study, the effects of inclined shaft angle on the hydro-acoustic performance of cavitating marine propellers are investigated by a numerical method developed before and Brown's empirical formula. The cavitating blades are represented by source and vortex elements. The cavity characteristics of the blades such as cavitation form, cavity volume, cavity length etc., are computed at a given cavitation number and at a set advance coefficient. A lifting surface method is applied for these calculations. The numerical lifting surface method is validated with experimental results of DTMB 4119 model benchmark propeller. After calculation of hydrodynamic characteristics of the cavitating propeller, noise spectrum and overall sound pressure level (OASPL) are computed by Brown's equation. This empirical equation is also validated with another numerical results found in the literature. The effects of inclined shaft angle on thrust coefficient, torque coefficient, efficiency and OASPL values are examined by a parametric study. By modifying the inclination angles of propeller, the thrust, torque, efficiency and OASPL are computed and compared with each other. The influence of the inclined shaft angle on cavity patterns on the blades are also discussed.

Basic Study of the Improvement of PSD Output by Inclined Light Input (PSD의 출력특성향상을 위한 경사 입력광의 특성해석에 대한 기본연구)

  • Kweon, Hyun-Kyu;Park, Chang-Yong
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.9 no.4
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    • pp.53-58
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    • 2010
  • In this paper, the output characteristics of PSD(Position Sensetive Detector) used in measurement system are described. Most of the precision measurment systems are accomplished by a laser diode(LD), a photo diode(PD) and PSD(Position Sensetive Detector), which are used in reflection of mirror or projection of infrared spectrometer. But it is especially restricted by resolution of PD and PSD in nano-measurement. A new inclined light methods into the PSD are employed in the surface measurement system for increasing the resolution. As the results, we can know that the output characteristics of detective senser (PSD) become more than 2 or 3 times by changing inclined angle(range: 5 degree) compared with common angle. In addition, the experiment results are confirmed that the change of inclined angle is not affecting to the linearity and repeating.

Effect of Tunnel Entrance Shape of High Speed Train on Aerodynamic Characteristics and Entry Compression Wave (고속전철의 터널입구 형상이 공력특성 및 터널입구 압축파에 미치는 영향)

  • Jeong, Soo-Jin;Kim, Woo-Seung;Zhu, Ming
    • Transactions of the Korean Society of Automotive Engineers
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    • v.12 no.6
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    • pp.111-118
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    • 2004
  • The work presented in this paper concerns the aerodynamic characteristics and compression wave generated in a tunnel when a high speed train enters it. A large number of solutions have been proposed to reduce the amplitude of the pressure gradient in tunnels and some of the most efficient solutions consist of (a) addition ofa blind hood, (b) addition of inclined part at the entrance, and (c) holes in the ceiling of the tunnel. These are numerically studied by using the three-dimensional unsteady compressible Euler equation solver with ALE, CFD code, based on FEM method. Computational results showed that the smaller inclined angle leads to the lower pressure gradient of compression wave front. This study indicated that the most efficient slant angle is in the range from $30^{\circ}$ to $50^{\circ}$. The maximum pressure gradient is reduced by $26.81\%$ for the inclined angle of $30^{\circ}$ as compared to vertical entry. Results also showed that maximum pressure gradient can be reduced by $15.94\%$ in blind hood entry as compared to $30^{\circ}$ inclined tunnel entry. Furthermore, the present analysis showed that inclined slant angle has little effect on aerodynamic drag. Comparison of the pressure gradient between the inclined tunnel hood and the vertical entry with air vent holes indicated that the optimum inclined tunnel hood is much more effective way in reducing pressure gradient and increasing the pressure rise time.

A Study on Fatigue Crack Growth Analysis of Inclined Cracked Plate with Composite Patched Repair (경사균열을 갖는 복합재료 보강판의 피로균열 성장에 관한 연구)

  • Chung, Ki-Hyun;Yang, Won-Ho;Kim, Cheol
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.12
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    • pp.2091-2099
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    • 2001
  • Fatigue crack growth behavior of inclined cracked Al 6061-T6 thick aluminum plate(6mm) repaired with the bonded composite patch was studied. A 0°inclined crack bonded reinforced composite patch and 15°, 30°, 45°, 60°inclined crack plates were tested. The effect of patch and inclined angle were studied and compared to each other. Also we investigated to the crack propagation direction and debonding behavior during the fatigue crack growth test. In this paper. a study was con(ducted to get an fatigue life, fatigue crack growth ratio and crack growth direction. Finally, the effectiveness of composite patch on inclined cracked plate was investigated. The results demonstrated thats there was a definite variation in fatigue life and fatigue crack growth behavior depending on the inclined crack angle.