• Title/Summary/Keyword: slip-form

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Critical Moisture and Pore Structure of Clay Based Consolidated Body (점토계 고형화소지의 임계함수율과 기공구조)

  • 이기강;박천주;김유택;김석범;김정환
    • Journal of the Korean Ceramic Society
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    • v.34 no.5
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    • pp.528-534
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    • 1997
  • There have been many studies on the preparation of slip, forming and drying in the slip casting process. However, is has not been yet on the rheological properties of consolidated body which largely affect on the workability. It was investugated that the rheological properties of the consolidated bodies formed by slip casting in the form of cakes from well dispersed(slip C) and weakly agglomerated slip(slip B) in the clay and clay-fly ash systems. The state of dispersion of slip was found to affected the critical moisture content which was largely affected by the pore and moisture distribution of the consolidated body. The cake C show lower critical moisture content than cake B in the clay system. However, the cake B gives lower critical moisture content than cake C in the clay-fly ash system.

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Numerical Study on Blockage and Slip Characteristics of Centrifugal Compressor Impellers (원심압축기 임펠러의 Blockage와 Slip 특성에 관한 수치연구)

  • Oh, Jongsik
    • 유체기계공업학회:학술대회논문집
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    • 2000.12a
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    • pp.236-244
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    • 2000
  • As the second part of the author's study, the aerodynamic blockage and the slip factor of 8 centrifugal compressor impellers are investigated, when the flow rate is changed from numerical stall to choke, using three-dimensional Navier-Stokes analysis results. Based on all the exit blockage distributions, an improved model equation with two adjusting coefficients is developed for the use in design processes with the agile engineering purpose. A popular expression of constant slip factors, the Wiesner's equation, cannot be applied in design processes when more accurate prediction is strongly required at design and off-design points. Slip factor variation is found to be also influenced by the blade loadings at midspan. When the flow rate is changed, a pattern of the slip factor variations is assumed to be a simple form which can be explained using midspan blade loading distributions.

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THE CHARACTERISTICS OF FRETTING WEAR

  • Iwabuchi, Akira
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1996.05a
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    • pp.1-3
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    • 1996
  • The characteristics of fretting wear are reviewed. Fretting damage depends on slip amplitude and classified into three groups: (1) an annular damage according to Mindlin's analysis at microslip region, (2) strong adhesive deformation without loose wear particles at the intermediate region, and (3) formation of fine oxide particles at the gross slip region. The critical slip amplitude of fretting is the boundary between (2) and (3). The boundary slip amplitude depends on normal load. The wear rate increases and saturates with increasing slip amplitude. But it is constant by considering the critical amplitude. The role of oxide particles are discussed. Three different actions are noted: accelerating wear, preventing wear and insignificant effect. The oxide shows two opposing effect depends on normal load and slip amplitude. This is related to the removal rate from the interface (abrasive action) and compaction rate at the interface to form a protective layer. The effect of oxidation is significant to determine the wear and friction. The diffusion of oxygen is restricted at the small amplitude. As a result, crack formation at the boundary is a predominant damage, related to fretting fatigue damage.

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Fabrication of Light Aggregates Using the Fly Ash-Clay Slurry

  • Seunggu Kang;Lee, Kigang;Kim, Jungwan
    • Proceedings of the Korea Association of Crystal Growth Conference
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    • 1998.06a
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    • pp.81-86
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    • 1998
  • The light aggregates were fabricated by sintering green bodies made form the fly ash-clay alip. The content of fly ashes in the slip could be increased up to 70wt.% due to controlled rheological behavior of the slip, and the green body of uniform microstructure could be obtained by DCC(Direct Coagulation Casting)method. The apparent density, microstructure and compressive strength for sintered bodies fired at 1100∼1200$^{\circ}C$ were evaluated. The properties of light aggregates fabricated depend on slip density, particle behavior in the slip and sintering conditions. The sintered body prepared by firing a green body made from slip of density 1.60 at 1150$^{\circ}C$/2hr satisfied conditions of a light aggregate as apparent density of 1.49${\pm}$0.02 and compressive strength of 584${\pm}$62kg/$\textrm{cm}^2$.

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Interface monitoring of steel-concrete-steel sandwich structures using piezoelectric transducers

  • Yan, Jiachuan;Zhou, Wensong;Zhang, Xin;Lin, Youzhu
    • Nuclear Engineering and Technology
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    • v.51 no.4
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    • pp.1132-1141
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    • 2019
  • Steel-concrete-steel (SCS) sandwich structures have important advantages over conventional concrete structures, however, bond-slip between the steel plate and concrete may lead to a loss of composite action, resulting in a reduction of stiffness and fatigue life of SCS sandwich structures. Due to the inaccessibility and invisibility of the interface, the interfacial performance monitoring and debonding detection using traditional measurement methods, such as relative displacement between the steel plate and core concrete, have proved challenging. In this work, two methods using piezoelectric transducers are proposed to detect the bond-slip between steel plate and core concrete during the test of the beam. The first one is acoustic emission (AE) method, which can detect the dynamic process of bond-slip. AE signals can be detected when initial micro cracks form and indicate the damage severity, types and locations. The second is electromechanical impedance (EMI) method, which can be used to evaluate the damage due to bond-slip through comparing with the reference data in static state, even if the bond-slip is invisible and suspends. In this work, the experiment is implemented to demonstrate the bond-slip monitoring using above methods. Experimental results and further analysis show the validity and unique advantage of the proposed methods.

Effects of Tempering Temperature and Time on the Slip Melting Point of Fats (처리 온도 및 시간이 고형 유지의 상승 융점에 미치는 영향)

  • Yi, Young-Soo;Chang, Young-Sang;Shin, Zae-Ik
    • Korean Journal of Food Science and Technology
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    • v.23 no.1
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    • pp.19-24
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    • 1991
  • Among the conditions changes for the slip melting point of tempering temperature and time were studied. The results were treated below at $4^{\circ}C$, slip M.P. were not effected by tempering time. But slip M.P. of lard and palm oil had fallen treated at $10^{\circ}C$, the reason was that low melting triglycerides did not form the perfect crystals. Therefore, in order to measure the slip M.P. should be decrease the free energy and from stable crystallization of fats. Recommendable tempering temperature was treated at $4^{\circ}C$.

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The Influence of Contact Shape on the Slip Regime in Contact-induced Failure

  • Kim, Hyung-Kyu;Kang, Heung-Seok;Song, Kee-Nam
    • KSTLE International Journal
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    • v.2 no.2
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    • pp.85-92
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    • 2001
  • The variation of contact traction induced by different contact shapes is studied experimentally and theoretically. Considerations fer the contact shape are rounded, truncated and truncated with rounding punches. A fretting wear experiment is conducted with the contact configuration of the strip on the tube specimens. The strip specimen is pressed to form the end profile of a rounded and truncated with rounding punches shape. Wear on the tube is investigated, which is regarded as the slip region of the contact surface. Taken into consideration is the general solution of the normal traction in the case of the indentation by a punch with its end profile of the combination of parabolas. Then, partial slip solution is obtained numerically, which is compared with the wear on the tube. The radius of the rounding and the obliquity of the edge truncation affect the tractions considerably. It is found that the proper choice of the end profile can restrain the contact-induced failure such aswear.

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Push-out test on the one end welded corrugated-strip connectors in steel-concrete-steel sandwich structure

  • Yousefi, Mehdi;Ghalehnovi, Mansour
    • Steel and Composite Structures
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    • v.24 no.1
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    • pp.23-35
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    • 2017
  • Current form of Corrugated-strip connectors are not popular due to the fact that the two ends of this form need to be welded to steel face plates. To overcome this difficulty, a new system is proposed in this work. In this system, bi-directional corrugated-strip connectors are used in pairs, and only one of their ends is welded to the steel face plates on each side. The other end is embedded in the concrete core. To assemble the system, common welding devices are required, and welding process can be performed in the construction sites. By performing the Push-out test under static loading, the authors experimentally assess the effects of geometric parameters on ductility, failure modes and the ultimate shear strength of the aforesaid connectors. For this purpose, sixteen experimental samples are prepared and investigated. For fifteen of these samples, one end of the shear connectors is welded to steel face plates, and the other end is embedded in the concrete. Another experimental sample is prepared in which both ends are welded to the steel face plates. According to the achieved results, several relations are proposed for predicting the ultimate shear strength and load vs. interlayer slip (load-slip) behavior of corrugated-strip connectors. Moreover, these formulas are compared with those of the well-known codes and standards. Accordingly, it is concluded that the authors' relations are more reliable.

A Modified Shooting Method Technique for the Analysis of the Limited Slip Capacity of UHPFRC-NC Composite Structure

  • Han, Sang-Mook;Wu, Xiangguo;Kim, Sung-Wook;Kang, Su-Tae
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.1061-1064
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    • 2008
  • Shear connectors have a finite slip capacity because of the mechanism by which they transfer the shear between UHPFRC and NC elements. At high degree of shear connection, non-linear analysis techniques are required to allow for compressive plasticity and tensile cracking behaviour of the elements. As with all non-linear problems, a closed form solution is difficult to find. A Modified Shooting Method Technique is developed here for non-linear analysis of UHPFRC/concrete composite. The initial effective moment is derived according to the prestressing force. The composite structure is divided into small segments which length is much less than the length of the structure and it can be assumed that the forces and displacements within each segment are constant. An equivalent analysis in composite girders would be to fix the slip strain in each segment and develop a moment curvature relationship for this slip strain in each segment. Additive forces and moment analysis on each section of the segments are analyzed by MSMT. Finally the ultimate slippage of the interface can be evaluated by the MSMT model. This paper presents a nonlinear analysis method for limited slip capacity of UHPFRC-NC interface.

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