• 한국기계가공학회지
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• 제20권3호
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• pp.16-23
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• 2021

The fracture characteristic of the bonded interface under the application of a sliding load to a double cantilevered specimen manufactured using lightweight material was examined. Inhomogeneously bonded materials such as Al6061-T6, CFRP, and CFRP-Al were employed. In the experiment, the specimen was loaded on both directions by applying a shearing load to the bonding interface. The experimentally obtained stress, specific strength and energy release rate values were examined. CFRP exhibited excellent specific strength. The experimental results demonstrated that the inhomogeneous bonded material CFRP-Al exhibited an overall high performance in comparison with the single materials.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1283-1288
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• 2008

The FPCB is used as the important component of the sliding mechanism of mobile phones. FPCB have been used as jumper cables(fixed wiring) in various types of circuits because of their flexibility and bending property. The dominant failure mode of the FPCB is open that was caused by fatigue. The fatigue is repeated whenever the sliding is open, so it is a mainly cause of FPCB fatigue. We examined the bending-fatigue lifetime of FPCB. we focused on observing the contact resistance degradation of FPCB of mobile phones according to different test condition of bending strain. As a result, it has proved that lifetime decreased by increasing bending strain.

• 한국분말재료학회지
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• 제13권6호
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• pp.450-454
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• 2006

Wear of steel plate was measured during unlubricated sliding against TiC composites. These composites consist of round TiC grains and steel matrix. TiC grain itself exhibits low surface roughness and round shape, which does not bring its counterpart into severe damage from friction. In our work a classical experimental design was applied to find out a dominant factor in counterpart wear. The analysis of the data showed that only the applied load has a significant effect on the counterpart wear. Wear rate of counterpart increased non-linearly with applied load. Amount of wear was discrepant from expectation of being in proportion to the load by analogy with friction force. Our experimental result from treating matrix variously revealed bimodal wear behavior between the composites and counterpart where a mode seems to result from the special lubricant characteristic of TiC grains, and the other is caused by metal-to-metal contact. The two wear mechanisms were discussed.

• Journal of Electrical Engineering and Technology
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• 제9권1호
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• pp.214-230
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• 2014

This paper presents a high performance sensor less control four motorized wheels for electric vehicle. Firstly, we applied a sensor less master-slave DTC based control to both the two in wheel motors by using sliding mode observer for its quick response and its high reliability in electric vehicle application. Secondly, to overcome the possible loss of adherence of one of the four wheels which is likely to destabilize the vehicle a solution is proposed in this paper. Thirdly, a Fuzzy logic anti-skid control structure well adapted to the non-linear system is used to overcome the main problem of power train system in the wheel road adhesion characteristic. Various Simulation results have been include in this paper to show that the proposed control strategy can prevent vehicle sliding and show good vehicle stability on a curved path.

• 전기학회논문지
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• 제58권2호
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• pp.314-321
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• 2009

In this paper, the robust nonlinear observer will be developed for PEM fuel cell system. Nonlinear model of PEM fuel cell system is introduced to study the design problems of observer. Sliding mode observer is designed to estimate the cathode and anode pressures of PEMFC system. And a nonlinear state observer is also designed to estimate the other states such as supply manifold pressure, Oxygen pressure, Hydrogen pressure, return manifold pressure, etc. The validity of the proposed observer will be verified by using Lyapunov's stability analysis method.

• Tribology and Lubricants
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• 제18권4호
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• pp.260-266
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• 2002

In this study, the effects of oxide layer farmed on the wear tracks of TiN coated silicon wafer on friction and wear characteristics were investigated. Silicon wafer was used for the substrate of coated disk specimens, which were prepared by depositing TiN coating with 1 ${\mu}{\textrm}{m}$ in coating thickness. AISI 52100 steel ball was used fur the counterpart. The tests were performed both in air for forming oxide layer on the wear track and in nitrogen to avoid oxidation. This paper reports characterization of the oxide layer effects on friction and wear characteristics using X-ray diffraction(XRD), Auger electron spectroscopy(AES), scanning electron microscopy (SEM) and multi-mode atomic force microscope(AFM).

• International Journal of Automotive Technology
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• 제5권2호
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• pp.109-114
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• 2004

This paper presents a closed-loop evaluation of the Vehicle Stability Control (VSC) system using a vehicle simulator. Human driver-VSC interactions have been investigated under realistic operating conditions in the laboratory. Braking control inputs for vehicle stability enhancement have been directly derived from the sliding control law based on vehicle planar motion equations with differential braking. A driving simulator has been validated using actual vehicle driving test data. Real-time human-in-the loop simulation results in realistic driving situations have shown that the proposed controller reduces driving effort and enhances vehicle stability.

• 한국자동차공학회논문집
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• 제13권1호
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• pp.83-89
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• 2005

This paper presents vehicle stability control algorithm based on 3-DOF vehicle model. The brake control inputs have been directly derived from the sliding control law based on a three degree of freedom plane vehicle model with differential braking. The simulation has performed using a full nonlinear 3-dimensional vehicle model and the performance of the controller has been compared to that of a direct yaw moment controller. Simulation results show that the proposed controller can provide a vehicle with better performance than conventional controller with respect to brake actuation without compromising stability at critical driving conditions.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1993년도 춘계학술대회 논문집
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• pp.218-222
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• 1993

A sliding mode controller associated with the moving sliding surface is formulate for the tip position control of a single-link flexible manipulator. After establishing the plant model which characterizes a noncollocated control system, a discontinuous control law is then constructed by restricting that velocity state variables are not available from direct sensor measurements. Using the proposed control law favorable system responses are accomplished through shortening the reaching phase without increasing maximum control torque. Furthermore, a low sensitiveness to extraneous disturbance is obtained. Computer simulations are undertaken in order to demonstrate these superior control performance characteristics to be accrued from the proposed methodology.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2000년도 춘계 학술발표회 논문집 Proceedings of EESK Conference-Spring
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• pp.178-185
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• 2000

A set of tests were accomplished in order to get better insight of the basic material properties of masonry made of normal concrete brick and different type of mortar compositions. Three different types of test were performed. Masonry unit and prism were tested by compressive strength test, Masonry wallets were tested by compressive strength test. Masonry wallets were tested in diagonally under tension. A significant influence of different mortar compositions on compression strength of masonry prism was observed, The tests have shown that for diagonal compression three different mode of failure were possible : tension crack along the loaded diagonal sliding along a mortar joint and combined sliding and diagonal crack according to the adhesive strength of a mortar.