• 제목/요약/키워드: loading performance

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A Numerical Analysis of the Elastohydrodynamic Lubrication of Connecting Rod Bearings (커넥팅 로드 베어링의 EHL에 관한 수치해석)

  • 김병직;김경웅
    • Tribology and Lubricants
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    • v.12 no.3
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    • pp.63-71
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    • 1996
  • The connecting rod bearing, which is subjected to periodical dynamic loading, is an impoRant component of the reciprocating engine. In the operation of this bearing, significant parameters are the oil film thickness and the film pressure. Peak film pressures of 20-30 MPa are not uncommon. So the elastic deformation of the bearing housing can have a significant effect on the bearing performance. In this study, a numerical analysis of connecting rod bearing is investigated. Elastic deformation of the bearing housing is considered in the analysis. Separate hydrodynamic and structural analysis are coupled through a direct iterative process. It is shown that as the result of the elastic deformation of the bearing housing, the eccentricity ratio is increased, and the minimum value of the minimum film thickness and the maximum value of the maximum film pressure are decreased. The variations of rotational speed and cylinder pressure affect the minimum film thickness and the maximum film pressure variations of the connecting rod bearing.

Development of an integrated decision support system for FMS production planning and scheduling problems (FMS의 생산계획 및 일정계획을 위한 의사결정을 위한 의사결정 지원시스템의 개발)

  • 장성용;장병만;박진우
    • Korean Management Science Review
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    • v.8 no.1
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    • pp.51-70
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    • 1991
  • This paper discusses planning and scheduling problems for efficient utilization of an FMS and presents an integrated decision support system for FMS production planning and scheduling problems. The decision support system, FMSDS(Flexible Manufacturing Systems Decision Support System), includes of data of handling module, part selection module, loading module, load adjusting module, scheduling module and simulation module etc. This paper includes the solution methodology of each subproblem. And an integrated interface scheme between the subproblems is presented. The interface scheme considers the relationships between the subproblems and generates solution using hierarchical and looping approaches. FMSDS is made up of six alternative models considering 3 loading objectives and 2 production order processing strategies. Performance comparisons among 6 alternatives and other decision support systems are shown using the non-terminating simulation techniques.

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Three-dimensional numerical simulation and cracking analysis of fiber-reinforced cement-based composites

  • Huang, Jun;Huang, Peiyan
    • Computers and Concrete
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    • v.8 no.3
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    • pp.327-341
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    • 2011
  • Three-dimensional graphic objects created by MATLAB are exported to the AUTOCAD program through the MATLAB handle functions. The imported SAT format files are used to produce the finite element mesh for MSC.PATRAN. Based on the Monte-Carlo random sample principle, the material heterogeneity of cement composites with randomly distributed fibers is described by the WEIBULL distribution function. In this paper, a concept called "soft region" including micro-defects, micro-voids, etc. is put forward for the simulation of crack propagation in fiber-reinforced cement composites. The performance of the numerical model is demonstrated by several examples involving crack initiation and growth in the composites under three-dimensional stress conditions: tensile loading; compressive loading and crack growth along a bimaterial interface.

Performance improvement of SOC indicator for electric vehicle using hydrometer (온-라인 비중계를 이용한 전기자동차용 바테리 잔존용량계의 성능개선)

  • 박종건;임영철;박철수;류영재
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.423-426
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    • 1996
  • The conditions to be satisfied with SOC(State-of-Charge) indicator installed on the electric vehicle were that it should be used under frequent loading conditions and that it should enable the monitor to adjust to the aging effect. But, the state-of-charge test requires a lengthy stabilization period after discharge cycles and the ampere-hour test requires the knowledge of the battery capacity in terms of amp-hours. However, a monitoring technique combining the state-of-charge test to enable the monitor to adjust to the aging effect with the ampere-hour test to use under frequent loading condition is studied and implemented on a microcontroller-based circuit in this paper. Specially, optical fiber is used to realize hydrometer which is immune to electromagnetic interference and toxic environment and makes it possible to be used in a wide temperature range.

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A Neighborhood Beam Search Algorithm for Routing Yard-Side Equipment in Port Container Terminals (컨테이너 터미널에서 야드장비의 경로결정을 위한 이웃에 대한 빔 탐색 방식)

  • 김기영;김갑환
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 1998.10a
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    • pp.315-322
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    • 1998
  • It is discussed how to route yard-side equipment during the loading operation in port container terminals. The number of containers to be picked up at each yard-bay, as well as the route of a yard-side equipment (for example, transfer crane or straddle carrier) in a yard, are determined. The objective of the problem is to minimize the total container handling time in the yard. An encoding method to represent nodes in the search space is introduced utilizing inherent properties of the optimal solution by which the search space is greatly reduced. A beam search algorithm is suggested. A numerical experiment is carried out to compared the performance of the beam search algorithm with those of other approaches.

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Sensor Device Plug & Play for Ubiquitous Computing (유비쿼터스 컴퓨팅을 위한 센서 디바이스 Plug & Play)

  • Park, Jung-Sun;Eun, SeongBae;Yoon, Hyeon-Ju
    • IEMEK Journal of Embedded Systems and Applications
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    • v.7 no.3
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    • pp.151-156
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    • 2012
  • When mounting the sensor device in the way of Plug&Play, sensor device drivers need to be loaded and linked dynamically. Since a sensor node platform is based on small 8 bit MCU, dynamic loading and linking technique used in Windows and Linux can not be applied. In this paper, we present how to link and load dynamically sensor device drivers for sensor device Plug&Play. We implement a prototype and evaluate it to make sure that there is no performance degradation like sensor device driver connection speed and memory usage. Connection speed overhead increases to 0.2ms. Memory usage overhead increases to hundreds byte. It shows that there is no heavy influence in running the actual program.

A Study on the Sensitivity of Reinforced Concrete Element Design Factors (변형율속도변화에 대한 철근콘크리트부재 설계인자의 민감성 연구)

  • Sim, Jong Sung
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.9 no.4
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    • pp.9-14
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    • 1989
  • A strain rate-dependent element model was used to study the loading rate-sensitivity of R/C beams and columns with different design factors. Conclusions were derived regarding the differences between the element axial/flexural performance under impulsive and quasi-static loads. Practical design formalas for predicting the loading rate-dependent axial and flexural strengths of R/C elements were also suggested.

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Study on Damping Characteristics of Hydropneumatic Suspension Unit of Tracked Vehicle

  • Cho, Jin-Rae;Lee, Hong-Woo;Yoo, Wan-Suk;Lee, Jin-Kyu
    • Journal of Mechanical Science and Technology
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    • v.18 no.2
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    • pp.262-271
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    • 2004
  • Hydropneumatic suspension unit is an important part of tracked vehicles to absorb external impact load exerted from the non-paved road and the cannon discharge. Its absorption performance is strongly influenced by both damping and spring forces of the unit. In this paper, we numerically analyze the damping characteristics of the in-arm-type hydropneumatic suspension unit (ISU) by considering four distinct dynamic modes of the ISU damper: jounce-loading, jounce-unloading, rebound-loading and rebound-unloading. The flow rate coefficients determining the oil flow rate through the damper orifice are decided with the help of independent experiments. The wheel reaction force, the flow rate at cracking and the damping energy are parametrically investigated with respect to the orifice diameter and the wheel motion frequency.

Behavior of light weight sandwich panels under out of plane bending loading

  • Ganapathi, S. Chitra;Peter, J. Annie;Lakshmanan, N.;Iyer, N.R.
    • Steel and Composite Structures
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    • v.21 no.4
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    • pp.775-789
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    • 2016
  • This paper presents the flexural behavior & ultimate strength performance of innovative light weight sandwich panels of size $3{\times}1.2m$ with two different solidity ratios viz. 0.5 and 0.33 under out of plane bending load. From the experimental studies, it is observed that the flexural strength and the stiffness are increased by about 46% and five folds for lesser solidity ratio case. From the measured strains of the shear connectors, full shear transfer between the concrete wythes is observed. The yielding occurred approximately at 4% and 0.55% of the ultimate deformation for 100 mm & 150 mm thick panels, which shows the large ductility characteristics of the panels. From the study, it is inferred that the light weight sandwich panels behave structurally in a very similar manner to reinforced concrete panels. Further from the numerical study, it is observed that the numerical values obtained by FE analysis are in good agreement with the experimental observations.

Behavior of geopolymer and conventional concrete beam column joints under reverse cyclic loading

  • Raj, S. Deepa;Ganesan, N.;Abraham, Ruby;Raju, Anumol
    • Advances in concrete construction
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    • v.4 no.3
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    • pp.161-172
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    • 2016
  • An experimental investigation was carried out on the strength and behavior plain and fiber reinforced geopolymer concrete beam column joints and the results were compared with plain and steel fiber reinforced conventional concrete beam column joints. The volume fraction of fibers used was 0.5%. A total of six Geopolymer concrete joints and four conventional concrete joints were cast and tested under reversed cyclic loading to evaluate the performance of the joints. First crack load, ultimate load, energy absorption capacity, energy dissipation capacity stiffness degradation and moment-curvature relation were evaluated from the test results. The comparison of test results revealed that the strength and behavior of plain and fiber reinforced geopolymer concrete beam column joints are marginally better than corresponding conventional concrete beam column joints.