• Title, Summary, Keyword: End effect

Search Result 3,832, Processing Time 0.05 seconds

A Case Study of large diameter steel pipe pile Foundation for Offshore LNG Facility (해상 LNG 인수시설 대구경 강관말뚝 시공 사례 연구)

  • You, Dae-Young;Kim, Hyung-Wook;Jang, Woo-Young;Choi, Ki-Byung;Cho, Sung-Han
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • /
    • pp.70-77
    • /
    • 2010
  • In this paper, a case study of drivability and bearing capacity of large diameter steel pipe piles at PTT LNG site in Thailand is introduced. The LNG facilities were designed to be founded on steel pipe pile foundations driven into the weathered rock formation overlaid by sand layers. The drivability analyses of open ended pipe piles were carried out using GRL WEAP program and the bearing capacities of the piles were estimated. Dynamic load tests were performed to evaluate end bearing resistance, and it is shown that the measured end bearing resistance is smaller than the calculated end bearing because the plugging does not develop sufficiently in case of large diameter pipe piles.

  • PDF

The cause examination of the crack of the end beam for welding structure type bogie (용접구조형 대차 엔드빔의 균열원인 규명)

  • Hong Jai-Sung;Ham Young-Sam;Lee Dong-Hyong;Sea Jung-Won
    • Proceedings of the KSR Conference
    • /
    • /
    • pp.726-731
    • /
    • 2004
  • Bogie is the connection device between carbody and wheel in railway vehicles. It is the core part that exert a important effect on the passenger safety and running safety. Bogie largely consists of bogie frame, suspension, brake, wheel set. Static and Dynamic load have acted on it complexly. When the bogie is designed, finite element method, static load test, fatigue test, running test should be considered. Some bogie frame of high speed railway freight car have the problem. It's end beam was cracked. The crack of the end beam have a bad effect on brake system. In that case, the cars would be in danger of derailment.

  • PDF

Machining Characteristics in High Speed Endmill Operation Considering Clearance Angle (엔드밀 가공 시 여유각을 고려한 가공특성)

  • 박정남;고성림
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.21 no.8
    • /
    • pp.43-49
    • /
    • 2004
  • The objective of this research is to investigate the effect of clearance angle on cutting performance in high speed end milling operation. The tool geometry parameters have complex relationship with cutting process parameter. In order to explain the effect of clearance angle, 2D turning operation in lathe and end milling operations are performed. Tools with different clearance angles are manufactured. Cutting forces, machining accuracy and tool life are examined according to the change of clearance angle. As clearance angle increases, cutting force decreases and machining accuracy improves. But it has been proved that there exists the optimal clearance angle according to the diameter of end mill for maximum tool life which is measured by frank wear.

A Structural Analysis and Optimization of a 60 N.m Class Flexible Disk Coupling (60 N.m급 플렉서블 디스크 커플링 구조해석 및 최적화)

  • Lee, H.K.;Kim, B.R.;Kim, S.M.;Kim, J.B.
    • Journal of The Korean Society of Manufacturing Technology Engineers
    • /
    • v.22 no.5
    • /
    • pp.774-781
    • /
    • 2013
  • A structural analysis was carried out for a 60 N.m class flexible disk coupling. Flexible disk couplings are used to transmit power between two shafts. When a flexible coupling is used, some amount of misalignments such as angle of deviation and end play can be allowed in assembling the shafts. However, the maximum allowable misalignment should be decided to guarantee the fatigue life. In this study, the effect of the angle of deviation and end play on the maximum stress was investigated. From the analysis results, it was shown that the angle of deviation has a greater effect on the maximum stress than the end play. Furthermore, the dimensions of the disk plate were optimized to realize a better design. From the optimization, the maximum stress could be reduced by up to 5.2%.

Fluctuating wind loads across gable-end buildings with planar and curved roofs

  • Ginger, J.D.
    • Wind and Structures
    • /
    • v.7 no.6
    • /
    • pp.359-372
    • /
    • 2004
  • Wind tunnel model studies were carried out to determine the wind load distribution on tributary areas near the gable-end of large, low-rise buildings with high pitch planar and curved roof shapes. Background pressure fluctuations on each tributary area are described by a series of uncorrelated modes given by the eigenvectors of the force covariance matrix. Analysis of eigenvalues shows that the dominant first mode contributes around 40% to the fluctuating pressures, and the eigenvector mode-shape generally follows the mean pressure distribution. The first mode contributes significantly to the fluctuating load effect, when its influence line is similar to the mode-shape. For such cases, the effective static pressure distribution closely follows the mean pressure distribution on the tributary area, and the quasi-static method would provide a good estimate of peak load effects.

Cutting Characteristics Variation of Inconel 718 in End Milling with different Helix Angles -(I) Up End Milling (인코넬 718의 엔드밀링시 헬릭스각에 따른 절삭특성 변화 -(I) 상향엔드밀링)

  • 태원익;이선호;최원식;양승한;이영문
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • /
    • pp.947-950
    • /
    • 2000
  • The purpose of this paper is to investigate the effect of the helix angle of endmilling cutter on the cutting characteristics of inconel 718 in up endmilling. To this end cutters with helix angle of $20^\circ$, $30^\circ$, $40^\circ$ and $50^\circ$ degree have been prepared. And a modified cutting force model in up end milling process is presented. Using this cutting force components of 4-tooth endmills with various helix angles have been predicted. Predicted values of cutting force components are well coincide with the measured ones. As helix angle increases overlapping effects of the active cutting edges increase.

  • PDF

Optimum Working Condition of Surface Roughness for End-Milling Using Taguchi Design (다구찌 기법을 이용한 엔드밀 가공시 최적 표면거칠기를 위한 가공조건선정)

  • 이상재;배효준;전태옥;박흥식
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • /
    • pp.553-556
    • /
    • 2003
  • End-milling have been used in the industrial world because it is very effective to the manufacture of mechanical parts with various shape. Recently the end-milling processing is needed the high-precise technique with good surface roughness and rapid time in aircraft, automobile part and molding industry. Therefore this study carried to decide the optimum cutting condition for surface roughness and rapid manufacturing time using design of experiment and ANOVA. From the results of experimentation, surface roughness have an effect on cutting direction, spindle speed and depth of cut. And then the optimum condition used Taguchi design is upward cutting in cutting direction, 600rpm in spindle speed, 240mm/min feed rate, 2mm in axial depth of cut and 0.25mm radial depth of cut. By using design of experiment, it is effectively represented shape characteristics of working surface in end-milling.

  • PDF

Presumption for Mutual Relation of the End-Milling Condition on Surface Roughness of ST S304 by Regression Analysis (회귀분석을 이용한 STS304의 표면정도에 미치는 엔드밀 가공조건의 상관관계 추정)

  • Ryu, M.R.;Lee, S.J.;Bae, H.J.;Jin, D.K.;Jun, T.O.;Park, H.S.
    • Proceedings of the KSME Conference
    • /
    • /
    • pp.1822-1827
    • /
    • 2003
  • End-milling have been used widely in industrial system because it is effective to a material manufacturing with various shape. Recently the end-milling processing is needed the high-precise technique with good surface roughness and rapid time in precision machine part and electronic part. The optimum surface roughness has an effect on end-milling condition such as, cutting direction, spindle speed, feed rate and depth of cut, etc. Therefore this study was carried out to presume for mutual relation of end-milling condition to get the optimum surface roughness by regression analysis. The results shown that coefficient of determination($R^{2}m$) of regression equation has a fine reliability over 80% and regression equation of surface rough is made by regression analysis.

  • PDF

Temperature Effect on the Configurational Properties of an n-Decane Chain in Solution

  • Oh, In-Joon;Ree, Tai-Kyue
    • Bulletin of the Korean Chemical Society
    • /
    • v.5 no.4
    • /
    • pp.162-167
    • /
    • 1984
  • Equilibrium and dynamical behaviors of an n-alkane poymer (decane) in solution have been investigated by a molecuar dynamics simulation method. The polymer is assumed to be a chain of elements $(CH_2)$ interconnected by bonds having a fixed bond length and bond angle, but esch bond of the polymer is allowed to execute hindered internal rotation. The calculation explicitly considers the molecular naturer of solvent by including the intermolecular interactions between slovent-solvent molecules and chain element-solvent molecule. We present the results of calculations on (1) equilibrium properties (the solvent molecule-chain element pair correlation function, chain element-chain element pair correlation function, the mean square end-to-end distance and the mean square radius of gyration of the polymer) and (2) dynamic properties (four different autocorrelation functions, namely, the autocorrelation functions for the end-to-end distance and the radius of gyration, and the velocity autocorrelation functions for the center of mass and the end point of the chain). We found that the physical properties of the polymer chain depends sensitively on temperature. Comparison of the present work with other authors' results is also presented.

  • PDF

An Analysis of Dynamic Critical Loads for Low Parabolic Arches with Different End Conditions (지지조건을 고려한 낮은 포물선 아치의 동적 임계하중의 해석)

  • 박승범
    • Magazine of the Korean Society of Agricultural Engineers
    • /
    • v.28 no.2
    • /
    • pp.87-92
    • /
    • 1986
  • The differential equation, which can determine the dynamic critical loads for low parabcoic arches, is derived in this study. The dynamic critical loads of the parabolic arches subjected to a concentrated step load are nummerically analyzed for the changes of load positions. In cases of arches with different end conditions (both hinged, fixed hinged, both fixed), the effect of end conditions and that of the rises are investigated in detail. The summary of the results are the following: 1)The snapthrough does not occur when the rise of arch is very low, and the bifurcation appears clearly as the rise of arch increases. 2)The regions in which the dynamic critical loads are not defined for the both ends fixed are broader than that for the both ends hinged. 3)For all case, the load positions of minimum dynamic critical loads exsit at the near position from the end hinged. Thus, the results obtained in present study show that the magnitude of dynamic critical loads, the load positions of minimum dynamic critical loads and the regions in which the dynamic critical loads are not defined depend on end conditions of arches.

  • PDF