• Structural Monitoring and Maintenance
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• 제5권1호
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• pp.129-150
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• 2018

This paper presents the structural performance monitoring of an urban footbridge located in Hangzhou, China. The structural health monitoring (SHM) system is designed and implemented for the footbridge to monitor the structural responses of the footbridge and to ensure the structural safety during the period of operation. The monitoring data of stress and displacement measured by the fiber Bragg grating (FBG)-based sensors installed at the critical locations are used to analyze and assess the operation performance of the footbridge. A linear regression method is applied to separate the temperature effect from the stress monitoring data measured by the FBG-based strain sensors. In addition, the static vertical displacement of the footbridge measured by the FBG-based hydrostatic level gauges are presented and compared with the dynamic displacement remotely measured by a machine vision-based measurement system. Based on the examination of the monitored stress and displacement data, the structural safety evaluation is executed in combination with the defined condition index.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.509-512
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• 1995

A new modeling incorporating the role of control arm is proposed for the Macpherson type suspension system. Vertical displacement of the sprung mass and angular displacement of the control arm are selected as main control variables in the new modeling. With the same values of suspension vehicle parameters the conventional modeling and the new modeling are compared in terms of open loop characteristics.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.503-506
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• 2000

Molecular switching in azobenzene mixed monolayers on a water surface was investigated by means of Maxwell displacement current(MDC) measurement. It was found that the change in the vertical component of the dipolemoment of the mixed monolayer during visible light irradiation was almost the same as that flowing during UV light irradiation. Also MDC was generated but it depended on the molar ratio. As a result. It's phtoisomerization progressed by 8A5H in mixed films.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.748-751
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• 2001

Monoleaflet polymer artificial heart valve was known to show remarkable improvement in antithrombosis and pressure drop compared with other type of artificial valve. In this investigation monoleaflet the vertical and horizontal deflection pattern of polymer heart valve with three types of supporting members straight member, and two curved members was analysed using the large deformation nonlinear finite element method.

• 한국정밀공학회지
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• 제20권3호
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• pp.120-124
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• 2003

Monoleaflet polymer artificial heart valve was known to show remarkable improvement in antithrombosis and pressure drop compared with other type of artificial valve. In this investigation of monoleaflet heart valve the vertical and horizontal deflection pattern of polymer heart valve with three types of supporting members, straight member and two curved members were analysed using the large deformation nonlinear finite element method.

• 한국공간구조학회논문집
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• 제22권4호
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• pp.81-88
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• 2022

The paper introduces an experimental program for the newly developed vertical joints between Precast Concrete (PC) walls to improve their in-plane shear capacity. Compared to the existing vertical joints, two types of vertical joints were developed by increasing the transverse reinforcement ratio and improving frictional force at the joint interface. A total of four specimens including the Reinforced Concrete (RC) wall and PC walls with developed vertical joints were designed and constructed. The constructed specimens were experimentally investigated through monotonic shear tests. The observed damage, load-deformation relationship, strain and strength are investigated and compared with the cases of RC wall specimen. Experimental results indicate that the maximum force and initial stiffness of the PC wall with proposed vertical joints were decreased by comparing with those of RC wall. However, the ultimate displacement increased by up to 217.30% compared to the RC wall specimen. In addition, brittle failure did not occurred and relatively few cracks and damages occurred.

• 대한치과교정학회지
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• 제49권3호
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• pp.150-160
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• 2019

Objective: This study aimed to analyze the effect of changing various parameters of the bone-borne rapid palatal expander (RPE) using the finite element method (FEM). Methods: In eight experimental groups, we investigated the effect of the number, position, and length of miniscrews; positional changes of the expander; and changes in the hook length on maxillary expansion. In finite element analysis, we compared the magnitude and distribution of stress, and the displacement changes following expansion of the bone-borne RPE. Results: When we compared the number and position of miniscrews, placing miniscrews in the anterior and posterior sides was advantageous for maxillary expansion in terms of stress distribution and displacement changes. Miniscrew length did not significantly affect stress distribution and displacement changes. Furthermore, anteroposterior displacement of the expander did not significantly affect transverse maxillary expansion but had various effects on vertical changes of the maxilla. The maxilla rotated clockwise when the miniscrews were placed in the anterior region. The hook length of the expander did not show consistent results in terms of changes in stress distribution and magnitude or in displacement changes. Conclusions: The findings of this study suggest that changes in the location and length of the miniscrews and displacement of the bone-borne RPE could affect the pattern of the maxillary expansion, depending on the combination of these factors.

• Computers and Concrete
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• 제29권2호
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• pp.69-79
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• 2022

For long underground box utility tunnels, post-tensioned precast concrete is often used. Between precast tunnel segments, sealed waterproof flexible joints are often specified. Fault displacement can lead to excessive deformation of the joints, which can lead to reduction in waterproofing due to diminished contact pressure between the sealant strip and the tunnel segment. This paper authenticates utilization of a finite element model for a prefabricated tunnel fault-crossing founded on ABAQUS software. In addition, material parameter selection, contact setting and boundary condition are reviewed. Analyzed under normal fault action are: the influence of fault displacement; buried depth; soil friction coefficient, and angle of crossing at the fault plane. In addition, distribution characteristics of the utility tunnel structure for vertical and longitudinal/horizontal relative displacement at segmented interface for the top and bottom slab are analyzed. It is found that the effect of increase in fault displacement on the splice joint deformation is significant, whereas the effects of changes in burial depth, pipe-soil friction coefficient and fault-crossing angle on the overall tunnel and joint deformations were not so significant.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
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• pp.530-533
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• 2006

This thesis investigates the behavior of precast wall systems with a new vertical connection which are proportioned by the displacement based design. The proposed precast wall systems are supposed to provide additional spaces and seismic strengthening in remodeling existing residential buildings. For a fast remodeling constructions using PC walls require an efficient, economic fabrication method. A C-type vertical connections for PC wall systems is proposed for transfer of bending moment between walls in the vertical direction while a shear key in the center of wall is prepared to transfer shear forces by bearing. The proposed vertical connection allows us easy fabrication because of different direction of slots at the edges of wall. The dimension of C-type connection components are determined by engineering models and a series of test.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1062-1067
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• 2007

This study presents an experimental technique to monitor the dynamic behavior of the railway bridge system simultaneously using multiplexed fiber Bragg grating (FBG) sensors. The measuring quantities include stains, curvatures, vertical deflections, and vertical accelerations. The strains are directly measured from multiplexed FBG sensors at various locations of the test bridge followed by curvature calculations based on the plane section assumption. Vertical deflections are then estimated using the Bernoulli beam theory and regression analysis. Finally, vertical accelerations are obtained from the numerical differentiation in time domain. In order to verify the proposed method, several conventional electric strain gauges, displacement transducers, and accelerometers are installed at the mid-span of the bridge for comparisons. A test train is passed over the bridge to monitor the dynamic response of the bridge. The monitoring results show that the multiplexed FBG sensing system is able to capture the essential behavior of the test bridge while resolving wiring problem in practice.