• Title, Summary, Keyword: camber

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Fatigue Life Evaluation of Diesel Locomotive Car body Considering Camber Effect (캠버를 고려한 디젤기관차 차체 피로수명평가)

  • Jun, Hyun-Kyu;Lee, Dong-Hyung;Kim, Jae-Chul;Lee, Chan-Woo
    • Proceedings of the KSME Conference
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    • pp.372-377
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    • 2008
  • Camber with positive deflection is one of the very important design parameters in the manufacture of railway coach. Positive camber is defined as concave shape such as an arch and it increases the strength of structure remarkably. But during the operation of a structure, the positive camber turns into negative camber and it loses the strength of structure. Therefore we should consider the camber effect when we evaluate the fatigue strength of negative cambered structure. For this purpose, we made a model of negative cambered locomotive car body and performed structural analysis and also we measured the dynamic loads at critical points during commercial line operation. Fatigue strength of locomotive was calculated by applying Miner's damage accumulation rule. Fatigue strength of the two locomotives which have different camber were compared to find out the effect of camber on dynamic load amplitude. We found that the more negative camber a locomotive had, the shorter fatigue strength obtained.

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Analysis of Vehicle Handling Performance due to Camber Angle Change of Rear Wheel (후륜 캠버각 변화가 차량 조종성능에 미치는 효과 분석)

  • Park, Seong-Jun;Sohn, Jeong-Hyun
    • Transactions of the Korean Society of Automotive Engineers
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    • v.18 no.2
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    • pp.67-73
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    • 2010
  • In this study, a camber angle generating mechanism for rear suspension is suggested. An experimental device is implemented and tested. A full vehicle model with camber angle generating device by using ADAMS/Car is modeled. Rear left wheel and rear right wheel have 5 different camber angles in the simulations, respectively. Step steer and pulse steer simulations are carried out for investigating the effects of vehicle handling performance due to camber angle control of rear suspension. According to the results, the camber angle of rear suspension affects the vehicle handling performance during both simulations. Therefore, when the vehicle makes the right turn or left turn, left and right wheel should have the proper orientation for improving the handling performance, respectively.

Effects on Vehicle Handling Performance according to Camber Angle Change of Front and Rear Wheel (전륜 및 후륜 캠버각 변화에 따른 차량 조종성능 효과 분석)

  • Park, Seong-Jun;Sohn, Jeong-Hyun
    • Transactions of the Korean Society of Automotive Engineers
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    • v.19 no.6
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    • pp.23-29
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    • 2011
  • In this study, a camber angle generating mechanism for front and rear suspension is suggested. An experimental device is implemented and tested. A full vehicle model with camber angle generating device by using ADAMS/Car is modeled. Step steer simulations are carried out for investigating the effects of vehicle handling performance due to camber angle change of front and rear wheel. According to results, the camber angle of rear suspension affects the vehicle handling performance during both simulations. Therefore, when the vehicle makes the right turn or left turn, left and right wheel of front and rear suspension should have the proper orientation for improving the handling performance, respectively.

A Study of Camber Effect on Contact Pressure Between Cam and Roller (캠-롤러 접촉압력에 대한 Camber효과에 관한 연구)

  • Chon, Seo-Hyeon;Lee, Sang-Don;Cho, Yong-Joo
    • Tribology and Lubricants
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    • v.26 no.1
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    • pp.56-60
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    • 2010
  • Contact pressure occurs whenever two surfaces contact between cam and roller. Especially excessive pressure peaks occur at the ends of the contact region. Such as scuffing or pitting will be induced when these operating conditions continuously occur on the surface. Camber effect is given to reduce damage by changing the shape of roller. The objective of this paper is to calculate contact pressure distribution by using a contact analysis considering camber and tilting angle. These results predict that camber effect of all machine components have influence on contact pressure distribution.

Changes of Camber on Lamination Conditions in alumina/Tungsten Cofiring Multilayer Package (알루미나/텅스텐 동시소성에 의한 다층 팩키지 제조시 적층조건에 따른 camber의 변화)

  • 성재석;구기덕;윤종광;이상진;박정현
    • Journal of the Korean Ceramic Society
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    • v.34 no.6
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    • pp.601-610
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    • 1997
  • In cofiring of multilayered alumina with tungsten, the change of camber with lamination condition was experimented and the effect of sintering shrinkage of alumina and tungsten was investigated. From the exact measurement of sintering shrinkage of tungsten thick film, as lamination pressure increased, the sintering shrinkage of alumina decreased but that of tungsten thick film was not changed. So it was though that the main factor which induced the sintering shrinkage difference between ceramics and metal with lamination condition was the change of sintering shrinkage of ceramics. In case of high lamination pressure, high green sheet density, the cofired specimen showed low camber due to low shrinkage difference between alumina and tungsten and there was a linear relation between camber and shrinkage difference. It was found that this shrinkage difference could change the thickness of tungsten film and the microstructure within via hole during cofiring.

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Vision-Based Camber and Optimal Cutting Line Detection Algorithm for Hot-Rolling Process (열연 공정에서의 영상을 이용한 캠버 및 최적 절단선 검출 알고리즘)

  • Kong, Nam-Wong;Moon, Jung-Hye;Park, Poo-Gyeon
    • Proceedings of the KIEE Conference
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    • pp.155-156
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    • 2007
  • This paper presents the vision-based camber and optimal cutting line detection algorithm for hot-rolling process. It is important to measure the camber of head and tail part of strips because many problems are caused by the camber in the hot-rolling process. The hot-rolling process has time constraints. The camber detection algorithm of head and tail parts requires fast and less complex for satisfying time constraints. The proposed algorithm consists of two parts: measurement of the camber in the head and tail part of strips and decision part of the optimal cutting line of hot-rolled strip. First, we obtain the camber value of the strip from the difference between the real center line and the center line of head, tail part. Second, the head and tail part of strips isn't suitable for strips connections. Therefore, the cutting process is needed in the hot-rolling process. The optimal cutting line is determined by the head and tail images obtained from cameras. The algorithm is applied into the vision system with two area cameras, Matrox image processing board and host PC for verification.

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Improvement of Vehicle Handling Performance due to Toe and Camber Angle Change of Rear Wheel by Using Double Knuckle (이중너클을 이용한 후륜 토 및 캠버각 변화를 통한 조종안정성 개선)

  • Sohn, Jeonghyun;Park, Seongjun
    • Transactions of the Korean Society of Automotive Engineers
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    • v.21 no.1
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    • pp.121-127
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    • 2013
  • In this study, suspension geometry is controlled to improve vehicle handling performance. The toe and camber of the rear suspension is controlled independently by using a double knuckle structure designed to enhance the vehicle cornering stability. Camber and toe changes in the rear wheel during high speed turning maneuver are important factors that influence the vehicle stability. Toe in the rear outer wheel plays a dominant role in cornering. A control algorithm for the camber and the toe angle input is developed to carry out the control simulation of the vehicle such as single lane change, the steady state cornering, the double lane change and the step steering simulation. Effects of the camber and toe angle control are analyzed from the computer simulations. A double lane change simulation revealed that the suspension mechanism with variable camber angle and variable toe angle decreases the peak body slip angle and peak yaw rate, 50% and 10%, respectively.

A Study on the Dynamic Setup of a Side Guide to Reduce Bar Camber at the Roughing Train in a Hot Strip Rolling Mill (열간 조압연공정에서 판 캠버 저감을 위한 사이드 가이드 동적설정에 관한 연구)

  • Byon, Sang-Min
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.15 no.1
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    • pp.34-41
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    • 2016
  • Bar camber is a phenomenon in which a material with a deformation gradient across its width is bent in the right or left direction in the roll gap. This paper proposes a dynamic setup approach for a side guide for reducing bar camber. A bar tracking scheme using a rotary encoder was adopted to fix an operation point for the side guide. The guiding pressure was utilized for measuring the actual width of the bar with camber. Based on the accurate position and width of the bar, the side guide was dynamically set and operated at the actual roughing train in a hot strip rolling mill. The amount of camber was reduced notably when the dynamic setup scheme was installed in the side guide. 78% of the bars tested had a camber in the range of ${\pm}20mm$, which was an improvement of 27% in terms of production yield.

Analysis of Two-Dimensional Flow around Blades with Large Deflection in Axial Turbomachine (전향도가 큰 축류터보기계의 블레이드 주위의 유동해석)

  • 원승호;손병진;최상경
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.15 no.1
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    • pp.229-240
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    • 1991
  • The large camber angle theory of turbomachine blade of compressor has been developed recently for the two-dimensional flow by Hawthorn, et al. However, in the above theory it was assumed that the fluid was incompressible and inviscid, and the blades had no thickness. In this study, the flow in a blade cascade being mounted in parallel fashion with blade of arbitrary thickness is studied in order to determine the effects of the camber angle on the performance characteristic of the blade section under the consideration of compressibility and viscosity of fluid. The panel method is used for potential flow analysis. The flow in the boundary-layer is obtained by solving the integral boundary-layer structure through the laminar, transitional , and turbulent flow using the pressure field determined from the potential flow. And then the viscous-inviscid interaction scheme is used for interaction of these two flows. For the determination of the variation in the outlet fluid angle influenced by deviation in cascade flow, the superposition method which is used for single foil is introduced in this analysis. By the introduction of this method, the effects of the deviation on outlet fluid angle and the resulting fluid angle are made to adjust for oneself through the calculation. As the result of this study, the blade of large camber angle, large incidence angle, large pitch-chord ratio has large viscous and compressible effect than those of small camber angle. Lift force increase as camber angle increases, but above 60.deg. of camber angle, lift force decrease as camber angle increases. But drag force increases linearly with camber angle increases in the entire region.

Analysis of the variability of deflection of a prestressed composite bridge deck

  • Staquet, Stephanie;Detandt, Henri;Espion, Bernard
    • Steel and Composite Structures
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    • v.4 no.5
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    • pp.385-402
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    • 2004
  • Nearly 400 composite railway bridge decks of a new kind belonging to the trough type with U-shaped cross section have been constructed in Belgium over the last fifteen years. The construction of these bridge decks is rather complex with the preflexion of precambered steel girders, the prestressing of a concrete slab and the addition of a 2nd phase concrete. Until now, they have been designed with a classical computation method using a pseudo-elastic analysis with modular ratios. Globally, they perform according to the expectations but variability has been observed between the measured and the computed camber of these bridge decks just after the transfer of prestressing and also at long-term. A statistical analysis of the variability of the relative difference between the measured camber and the computed camber is made for a sample of 36 bridge decks using no less than 10 variables. The most significant variables to explain this variability at prestressing are the ratio between the maximum tensile stress reached in the steel girders during the preflexion and the yield strength and the type of steel girder. For the same sample, the long-term camber under permanent loading is computed by two methods and compared with measurements taken one or two years after the construction. The camber computed by the step-by-step method shows a better agreement with the measured camber than the camber computed by the classical method. The purpose of the paper is to report on the statistical analysis which was used to determine the most significant parameters to consider in the modeling in order to improve the prediction of the behaviour of these composite railway bridge decks.