• Title/Summary/Keyword: Overlap length

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Stress Distribution and Strength Evaluation of Adhesive Bonded Single-lap Joints (단일겹침 접착제 접합부의 응력분포와 강도평가)

  • 이중삼;임재규;김연직
    • Journal of Welding and Joining
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    • v.19 no.3
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    • pp.342-347
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    • 2001
  • Recently, adhesive-bonding technique is wifely used in manufacturing structures. Stress and strain analysis of joints are essential to design adhesive-bonded joints structure. The single-lap adhesive joint is the design dominating the range of adhesive joints. In this study, single-lap specimens with different joint dimensions were used for the tensile-shear test and finite element calculation in of order to investigate the effect of overlap length and adhesive-bonding thickness on adhesive strength and stress distribution of the joints. Consequently, it was found that overlap lap size and thickness can be important parameters of structure joints using adhesive bonding, which is effected on adhesive strength.

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Localized evaluation of actuator tracking for real-time hybrid simulation using frequency-domain indices

  • Xu, Weijie;Guo, Tong;Chen, Cheng
    • Structural Engineering and Mechanics
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    • v.62 no.5
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    • pp.631-642
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    • 2017
  • Accurate actuator tracking plays an important role in real-time hybrid simulation (RTHS) to ensure accurate and reliable experimental results. Frequency-domain evaluation index (FEI) interprets actuator tracking into amplitude and phase errors thus providing a promising tool for quantitative assessment of real-time hybrid simulation results. Previous applications of FEI successfully evaluated actuator tracking over the entire duration of the tests. In this study, FEI with moving window technique is explored to provide post-experiment localized actuator tracking assessment. Both moving window with and without overlap are investigated through computational simulations. The challenge is discussed for Fourier Transform to satisfy both time domain and frequency resolution for selected length of moving window. The required data window length for accuracy is shown to depend on the natural frequency and structural nonlinearity as well as the ground motion input for both moving windows with and without overlap. Moving window without overlap shows better computational efficiency and has potential for future online evaluation. Moving window with overlap however requires much more computational efforts and is more suitable for post-experiment evaluation. Existing RTHS data from Network Earthquake Engineering Simulation (NEES) is utilized to further demonstrate the effectiveness of the proposed approaches. It is demonstrated that with proper window size, FEI with moving window techniques enable accurate localized evaluation of actuator tracking for real-time hybrid simulation.

Linearity Optimization of DG MOSFETs for RF Applications

  • Kim, Dong-Hwee;Shin, Hyung-Cheol
    • Proceedings of the IEEK Conference
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    • 2005.11a
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    • pp.897-900
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    • 2005
  • RF linearity of double-gate MOSFETs is investigated using accurate two-dimensional simulations. The linearity has been analyzed using the Talyor series. Transconductance is dominant nonlinear source of CMOS. It is shown that DGMOSFET linearity can be improved by a careful optimization of channel thickness, gate oxide thickness, gate length, overlap length and channel doping concentration. The minimum $P_{IP3}$ data are compared in each case. It is shown that DG-MOSFET linearity can be improved by a careful optimization of channel thickness, gate oxide thickness, gate length, overlap length and channel doping concentration..

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Accuracy Analysis of Extraction Methods for Effective Channel Length in Deep-Submicron MOSFETs

  • Kim, Ju-Young;Choi, Min-Kwon;Lee, Seong-Hearn
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.11 no.2
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    • pp.130-133
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    • 2011
  • A comparative study of two capacitance methods to measure the effective channel length in deep-submicron MOSFETs has been made in detail. Since the reduction of the overlap capacitance in the accumulation region is smaller than the addition of the inner fringe capacitance at zero gate voltage, the capacitance method removing the parasitic capacitance in the accumulation region extracts a more accurate effective channel length than the method removing that at zero gate voltage.

A Study on the Attrition of Maxillary Canine in Korea (상악 견치의 교모에 관한 연구)

  • Lim, Byung-Chul
    • Journal of Technologic Dentistry
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    • v.19 no.1
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    • pp.121-130
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    • 1997
  • This study was aimed to help the construction of naturally dental prosthesis by investigation of the factors affecting on the attrition position and attrition angle of maxillary canines. Therefore 163 complete cast of maxillary and mandibular extracted from the student of K. college were subjected for this study, and result through the study are as follows. 1. None attrite rate of the maxillary canine was 7%, of examined teeth. 2. Throughout mesiodistal attrition of 1) Throughout mesiodistal attrition area of the maxillary canines showed that mesial area and mid area of cusp was more frequence in attrition than distal area of it. 2) Sex, dental arch type, vertical overlap, horizontal overlap, did not affect significantly to throughtout mesiodistal attrition statistically 3. Througout labiolingual attrition area 1) Throughout labiolingual attrition area of the maxillary canines showed that attrition of the from lingual to labioncisal edge was more frequence than it of linguoincisal edge 2) It showed that attrition of the from lingual to labioincisal edge was more frequence when the length of horizontal overlap is shorter, by horizontal overlap 3) The attrition of the from lingual to labioincisal edge in maxillary left canines showed that male was more frequence in attrition than female. 4) Dental arch type, vertical overlap, did not affect signioficantly to labiolingual attrition, statistically. 4. Attrition angle 1) It showed that average attrition angle of the maxillary right canines were $19{\pm}11.02$ dagree, and it of left canines were $18{\pm}11.83$ degree. 2) It showed that famale have a bigger attrition angle than male, by sex. 3) It showed that attrition angle was bigger when the length of horizontal ovelap is bigger, by horizontal overlap.

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Strength of Composite Single-Lap Bonded Joints with Various Manufacturing Processes for Aircraft Application (항공용 복합재 단일겹침 접착 체결부의 제작공정에 따른 강도 연구)

  • Song, Min-Gyu;Kweon, Jin-Hwe;Choi, Jin-Ho;Kim, Hyo-Jin;Song, Min-Hwan;Shin, Sang-Joon
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.37 no.8
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    • pp.751-758
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    • 2009
  • Failure strengths of composite single-lap adhesive joints were investigated with various parameters such as manufacturing method, overlap length and adherend thickness. A total of 335 single-lap joint specimens were tested under tension. Specimens were fabricated with 4 different manufacturing processes; cocuring without and with adhesive, secondary bonding and co-bonding. Each manufacturing process has 5 different overlap lengths and 4 different thicknesses, respectively. As expected, failure strength is higher in thicker adherend joints and lower in larger overlap length specimens. Interesting result is that the secondary bonded joints show the higher strength than the cobonded and cocured joints with adhesive, and give close or even higher strength compared with non-adhesive cocured case.

A Parametric Study on the Strength of Single-Lap Bonded Joints of Carbon Composite and Aluminum (탄소 복합재-알루미늄 단일겹침 접착 체결부의 강도에 관한 인자연구)

  • Kim, Tae-Hwan;Seong, Myeong-Su;Choi, Jin-Ho;Kweon, Jin-Hwe
    • Composites Research
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    • v.20 no.5
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    • pp.34-42
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    • 2007
  • Strength and failure of adhesively bonded carbon composite-to-aluminum single-lap joints were studied by experiment. The main objective of this study is to investigate the effect of various parameters such as curing pressure for bonding, overlap lengths, and adherend thickness on the failure loads and modes of the bonded Joints with dissimilar materials. Experimental results show that the bonding pressure for composite-to-aluminum dissimilar materials should be 4 atm at the lowest. Failure load of the joints increases as the overlap length increases, but the strength (failure load divided by bonded area) decreases rapidly after the overlap width-to-length ratio is greater than 1. When the adherend thickness increase to double, bonding strength increase $12{\sim}55%$. Major failure mode of the joints is the delamination in the composite laminate and the location of delamination goes deeper into the laminates as the bonding pressure and overlap length increase.

Strength Evaluation of Adhesive Bonded Joint for Car Body (차체접합과 관련한 접합 강도 평가)

  • 이강용;김종성;공병석;우형표
    • Transactions of the Korean Society of Automotive Engineers
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    • v.6 no.1
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    • pp.143-150
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    • 1998
  • The evaluation of joint fatigue strength of light weight materials for electrical vehicle body has been performed through single lap joint tests with the design parameters such as joint style, adherend, bonding overlap length and bonding thickness. Fatigue strength was evaluated through 5-Hz, tension-tension, load controlled test with the stress ratio zero value. It is experimentally observed that fatigue strength of joint increases for the increase of overlap length. The combinations of Al-Al and Al-FRP adherends show that fatigue strength of joint is hardly changed for the increase of bonding thickness, but FRP-FRP adherend specimen shows that fatigue strength of joint increases after decreases for the increase of bonding thickness. Al-Al adherend specimen has much higher fatigue length than Al-FRP and FRP-FRP adherend specimens. Riveting at adgesive bonded joint gives little effect on fatigue strength.

Analysis for Series Resistance of Amorphous Silicon Thin Film Transistor (비정질 실리코 박막 트랜지스터의 직렬 저항에 관한 분석)

  • Kim, Youn-Sang;Lee, Seong-Kyu;Han, Min-Koo
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.43 no.6
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    • pp.951-957
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    • 1994
  • We present a new model for the series resistance of inverted-staggered amorphous silicon (a-Si) thin film transistors (TFT's) by employing the current spreading under the source and the drain contacts as well as the space charge limited current model. The calculated results based on our model have been in good agreements with the measured data over a wide range of applied voltage, gate-to-source and gate-to-drain overlap length, channel length, and operating temperature. Our model shows that the contribution of the series resistances to the current-voltage (I-V) characteristics of the a-Si TFT in the linear regime is more significant at low drain and high gate voltages, for short channel and small overlap length, and at low operating temperature, which have been verified successfully by the experimental measurements.

A Study on Flexural Rigidity of Two-row Overlap Pile Wall for Deep Excavation Support (대심도 굴착면 지지를 위한 2열 겹침말뚝의 휨 강성에 관한 연구)

  • Choi, Won-Hyuk;La, You-Sung;Kim, Bum-Joo
    • Journal of the Korean Geosynthetics Society
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    • v.17 no.1
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    • pp.33-43
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    • 2018
  • Two-row Overlap Pile wall is a novel retaining wall system with high flexural rigidity and waterproofing for deep excavation support currently being developed in Korea. The Two-row Overlap Pile wall is constructed by making an overlap between consecutive four-axis (or two-axis) auger piles which themselves are overlapped and arranged in zigzag manner. In this study, the flexural rigidity of the Two-row Overlap Pile wall, including the effect of cross-sectional shape, was examined using both theoretical and numerical approaches. The results of investigation suggested that the Two-row Overlap Pile wall formed with two-row piles exhibit greatly higher flexural rigidity than conventional one-row pile walls such as Cast in place pile (CIP) and Secant pile wall (SPW), whereas the effect of overlap length between piles on the flexural rigidity is relatively minimal.