• Geomechanics and Engineering
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• 제18권4호
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• pp.407-415
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• 2019

A controlled low strength material (CLSM) is a highly flowable cementitious material used for trench backfilling. However, when applying vertical loads to backfilled trenches, shear failure or differential settlement may occur at the interface between the CLSM and natural soil. Hence, this study aims to evaluate the characteristics of the interface friction between the CLSM and soils based on curing time, gradation, and normal stress. The CLSM is composed of fly ash, calcium sulfoaluminate cement, sand, silt, water, and an accelerator. To investigate the engineering properties of the CLSM, flow and unconfined compressive strength tests are carried out. Poorly graded and well-graded sands are selected as the in-situ soil adjacent to the CLSM. The direct shear tests of the CLSM and soils are carried out under three normal stresses for four different curing times. The test results show that the shear strengths obtained within 1 day are higher than those obtained after 1 day. As the curing time increases, the maximum dilation of the poorly graded sand-CLSM specimens under lower normal stresses also generally increases. The maximum contraction increases with increasing normal stress, but it decreases with increasing curing time. The shear strengths of the well-graded sand-CLSM interface are greater than those of the poorly graded sand-CLSM interface. Moreover, the friction angle for the CLSM-soil interface decreases with increasing curing time, and the friction angles of the well-graded sand-CLSM interface are greater than those of the poorly graded sand-CLSM interface. The results suggest that the CLSM may be effectively used for trench backfilling owing to a better understanding of the interface shear strength and behavior between the CLSM and soils.

• KIEAE Journal
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• 제9권3호
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• pp.3-12
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• 2009

The purpose of this study is to suggest ways to design for the environmental Interface of Long Life Housing. Research, improving the performance of the interface, is underway at the research organization of Long Life Housing. Infill system should accommodate the various changes in the space. So dismantlement, replacement, and repair of the act are essential. In this process, A lot of substance, which can damage or spoil the environment, may be produced. However, the eco-friendly aspects of the interface design of infill system is not made in the approach or evaluation. Therefore, this paper is to analyze the problem of Interface of Long Life Housing in terms of eco-friendly, and it try to find a design method, complemented in the next research.

• 제어로봇시스템학회논문지
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• 제13권3호
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• pp.242-248
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• 2007

In this paper, we implement the internet-based remote control system for intelligent robot. For remote control of the robot, it uses the socket communication of the TCP/IP. It consists of the user interface and the robot control interface. Robot control interface transmits the navigation and environmental informations of the robot into the user interface. In order to transmit the large environmental images, a JPEG compression algorithm is used. User interface displays the navigation status of the robot and transmits the navigation order into the robot control interface. Also, we propose the design method of the fuzzy controller using navigation data acquired by expert's knowledge or experience. To do this, we use virus-evolutionary genetic algorithm(VEGA). Finally, we have shown the proposed system can be operated through the real world experimentations.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.325-327
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• 2007

In this paper, we implement the internet- based remote control system for intelligent robot. For remote control of the robot, it uses the socket communication of the TCP/IP. It consists of- the user interface and the robot control interface. Robot control interface transmits the navigation and environmental informations of the robot into the user interface. In order to transmit the large environmental images, a JPEG compression algorithm is used. User interface displays the navigation status of the robot and transmits the navigation order into the robot control interface. Also, we propose the design method of the fuzzy controller using navigation data acquired by expert's knowledge or experience. To do this, we use virus-evolutionary genetic algorithm(VEGA). Finally, we have shown the proposed system can be operated through the real world experimentations.

• Geomechanics and Engineering
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• 제7권5호
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• pp.495-524
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• 2014

To investigate the soil-pile interactive performance under lateral loads, a set of laboratory model tests was conducted on remoulded test bed of soft clay and medium dense sand. Then, a simplified boundary element analysis had been carried out assuming floating pile. In case of soft clay, it has been observed that lateral loads on piles can initiate the formation of a gap, soil heave and the tension crack in the vicinity of the soil surface and the interface, whereas in medium dense sand, a semi-elliptical depression zone can develop. Comparison of test and boundary element results indicates the accuracy of the solution developed. However, in the boundary element analysis, the possible shear stresses likely to be developed at the interface are ignored in order to simplify the existing complex equations. Moreover, it is unable to capture the influence of base restraint in case of a socketed pile. To bridge up this gap and to study the influence of the initial stress state and interface parameters, a field based case-study of laterally-loaded pile in layered soil with socketed tip is explored and modelled using the finite element method. The results of the model have been verified against known field measurements from a case-study. Parametric studies have been conducted to investigate the influence of the coefficient of lateral earth pressure and the interface strength reduction factor on the results of the model.

• Tribology and Lubricants
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• 제17권1호
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• pp.1-9
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• 2001

Hard disk drives operate in various environmental conditions. Thus, it is necessary to assess the reliability of the head/disk interface under these conditions. In this work, stiction and acoustic emission signals were investigated under different temperature, humidity, and ambient pressure conditions. Also, track average amplitude was observed for disk failure in N$_2$environment. It is shown that failure of the head/disk interface occurs more readily at high temperature and low ambient pressure conditions.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1998년도 제28회 추계학술대회
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• pp.131-138
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• 1998

It is essential that hard disk drives perform reliable under various temperature, humidity, and ambient pressure conditions. In this paper the tribological characteristics of a head/disk interface are investigated under various environmental conditions. Specially, Contact-Start-Stop(CSS) tests were performed to assess the stiction and slider take-off behavior. It is shown that the surface damage is accelerated by high temperature and humidity as well as low ambient pressure.

• Structural Engineering and Mechanics
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• 제15권3호
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• pp.315-329
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• 2003

As shear occurs along a soil-structure interface, a localized zone with a thickness of several grain diameters will develop in soil along the interface, forming an interfacial layer. In this paper, the behaviour of a soil-structure interface is studied numerically by modelling the plane shear of a granular layer bounded by rigid plates. The mechanical behaviour of the granular material is described with a micro-polar hypoplastic continuum model. Numerical results are presented to show the development of shear localization along the interface for shearing under conditions of constant normal pressure and constant volume, respectively. Evolution of the resistance on the surface of the bounding plate is considered with respect to the influences of grain rotation.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.446-451
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• 2004

Over testing problems of satellites and theirs components have been issued due to their effects on satellite development cost and schedule. Force limited vibration tests were introduced as solution of the problems in 1980s. Over testing phenomena occurs due to the lack of similarity on interface impedance. Force limited vibration tests control interface force to simulate actual interface impedance. In this research, force limited vibration tests are applied on two satellites environmental tests. Force limits are calculated by using TDFS method and Semi-Empirical method. Four force sensors are employed to control interface force. The tests prove that force limited control reduced maximum interface acceleration in order of 3.

• Steel and Composite Structures
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• 제51권2호
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• pp.127-138
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• 2024

In this paper, structural behavior under fire conditions is comprehensively examined, and a novel software interface for testing interfaces efficiently is developed and validated. In order to accurately assess the response of structures to fire scenarios, advanced simulation techniques and modeling approaches are incorporated into the study. This interface enables accurate heat transfer analysis and thermo-mechanical simulations by integrating software tools such as CSI ETABS, CSI SAP2000, and OpenSees. Heat transfer models can be automatically generated, simulation outputs processed, and structural responses interpreted under a variety of fire scenarios using the proposed technique. As a result of rigorous testing and validation against established methods, including Cardington tests on scales and hybrid simulation approaches, the software interface has been proven to be effective and accurate. The analysis process is streamlined by this interface, providing engineers and researchers with a robust tool for assessing structural performance under fire conditions.