• 대한수의학회지
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• 제63권3호
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• pp.24.1-24.6
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• 2023

This study compared the biomechanical properties of bone-stapling techniques with those of other fixation methods used for stabilizing tibial tuberosity fractures using 3-dimensionally (3D)-printed canine bone models. Twenty-eight 3D-printed bone models made from computed tomography scan files were used. Tibial tuberosity fractures were simulated using osteotomy. All samples were divided into 4 groups. Group 1 was stabilized with a pin and tension-band wire; group 2, with a pin and an 8 mm-wide bone staple; group 3, with 2 horizontally aligned pins and an 8 mm-wide bone staple; and group 4 with a 10 mm-wide bone staple. Tensile force was applied with vertical distraction until failure occurred. The load and displacement were recorded during the tests. The groups were compared based on the load required to cause displacements of 1, 2, and 3 mm. The maximum failure loads and modes were recorded. The loads at all displacements in group 4 were greater than those in groups 1, 2, and 3. The loads at 1, 2, and 3 mm displacements were similar in groups 1 and 3. There was no significant difference between groups 1 and 3. Groups 1 and 4 provided greater maximum failure loads than groups 2 and 3. Failure occurred because of tearing of the nylon rope, tibial fracture, wire breakage, pin bending, and fracture around the bone staple insertion. In conclusion, these results demonstrate that the bone-stapling technique is an acceptable alternative to tension-band wire fixation for the stabilization of tibial tuberosity fractures in canine bone models.

• JSTS:Journal of Semiconductor Technology and Science
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• 제3권3호
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• pp.153-166
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• 2003

Failure analysis is fundamental to the design and development methodology of electrostatic discharge (ESD) devices and ESD robust circuits. The role of failure analysis (FA) in the models, methodology, band mechanisms evaluation for improving ESD robustness of semiconductor products in CMOS, silicon-on-insulator (SOI) and silicon germanium (SiGe) technologies will be reviewed.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1999년도 춘계학술대회논문집
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• pp.225-228
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• 1999

In a plastically deformed body the formation of a shear band is widely observed in the engineering materials during rapidly forming process for a thermally rate-sensitive material. The localized shear bond stems from evolution of a narrow region in which intensive plastic flow occurs. The shear band often plays as a precursor of the ductile fracture during a forming process. The objectives of this study are to investigate the localization behaivor by using numerical method thus predict the failure. In this work the implicit finite difference scheme is preformed due to the ease of covergence and the numerical stability. This study is based on an analysised material with hardening as well as thermally softening behavior which includes isotropy strain hardening. Furthermore this paper suggests that an anticipated and suggested a kinematic hardening constitutive equation be requried to predicte a more accurate strain level wherein a shear band occurs.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.574-580
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• 2009

This study is investigate the bending behavior of real size RC beams strengthened with carbon fiber sheets. For experimental study, 1 control beam and 8 strengthened beams of real size(4 NU-beams and 4 U-beams) are tested and compared. NU-beam has not a V-shaped band and V-beam has a V-shaped band. The variables of experiment are composed of the number of carbon fiber sheets, the existence of U-shaped band, and four point loading, etc. The experimental results showed that the strengthening system with U-shaped band controls the premature debonding and provides a more ductile failure mode than the strengthening system without V-shaped band. It can be found from the load-deflection curves that as the number of fiber sheets is increased, the maximum strength and the flexural rigidity is increased. For the strengthening method with carbon fiber sheets of the real size RC beams, it is required the finding a solution to the bonding problem.

• 구강회복응용과학지
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• 제40권2호
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• pp.100-106
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• 2024

조기 교정치료의 개입은 종종 성장하는 치열을 정상 교합으로 유도하는 것에서부터 시작된다. 유치의 상실로 인한 맹출 실패를 예방하는 가장 간단한 방법은 밴드 및 루프와 같은 공간 유지장치를 부착하는 것이다. 밴드 및 루프 공간 유지장치는 밴드의 픽업 인상 과정을 거쳐야 하며, 시멘트 소실과 탈회, 인접치의 locking과 같은 문제들을 갖고 있다. 이러한 문제를 해결하기 위해서 CAD/CAM을 이용한 band가 필요 없는 공간유지장치가 개발되었다. 본 증례는 밴드 없이 CAD/CAM을 이용하여 하악 제2소구치가 성공적으로 맹출할 수 있었기에 이를 보고하는 바이다.

• Geomechanics and Engineering
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• 제34권1호
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• pp.1-15
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• 2023

This study conducts uniaxial compression tests on intact and single crack-contained rocks to investigate the time-frequency domain characteristics of acoustic emission (AE) signals monitored during the deformation failure process. A processing approach, short-time Fourier transform (STFT), is performed to obtain the evolution characteristics of time-frequency domain of AE signals. The AE signal modes at different deformation stages of rocks are different. Five modes of AE signal are observed during the cracking process of rocks. The evolution characteristics of time-frequency domain of AE signals processed by STFT can be utilized to evaluate the damage process of rocks. The difference of time-frequency domain characteristics between intact and cracked rocks is comparatively analyzed. The distribution characteristics of frequency changing from a single band-shaped cluster to multiple band-shaped clusters can be regarded as an early warning information of damage and failure of rocks. Meanwhile, the attenuation of frequency enables the exploration of rock failure trends.

• Journal of Communications and Networks
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• 제1권3호
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• pp.158-165
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• 1999

This paper studies interconnection of DCS1800 and GSM900 dual-band networks. Two types of interconnection config-urations for GSM services, non-overlap and overlap, are described. We propose analytic and simulation models to investigate the ben-efit of the overlap configuration. Our results explain how the radio channel capacities, the inter-system handoff failure rate, the origi-nating call traffic ratio and the offered loads affect the system per-formance. This study indicates that with appropriate overlap con-figuration, the GSM dual-band network can significantly improve the quality of cellular service.

• 한국추진공학회지
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• 제11권6호
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• pp.18-25
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• 2007

열적으로 민감한 재료의 소성 변형에 있어서, 전단력에 의한 전단밴드(shear band)는 많은 공학적인 재료에서 관찰되고 있으며 전단밴드의 형성이 가속화됨에 따라 밴드의 변화량이 많고 폭이 좁은 국부화(localization) 현상이 발생하게 되는데, 이는 가공물에 치명적인 파단을 가져올 수 있는 현상이다. 본 연구에서는 텅스텐 중합금(tungsten heavy alloy, WHA)의 관통 메커니즘을 분석하기 위해 높은 변형률의 조건하에서 관찰될 수 있는 전단밴드(shear band)의 형성과 국부화 현상에 대하여 열적 조건을 고려하여, 고속변형률에서 다결정 금속의 전단밴드 구성에 기초를 둔 메커니즘을 수치적으로 연구하였다.

• 대한조선학회논문집
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• 제60권6호
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• pp.441-449
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• 2023

With the enforcement of environmental regulations by the International Maritime Organization, the market for eco-friendly ships is expanding, and ships using electric propulsion devices are emerging as a promising solution. Many studies have been conducted to predict the failure of ships, but most of them are mainly research on the main diesel engine of ships. As the ship's propulsion method changes, new data is needed to predict the failure of electric propulsion ships. In this paper aims to analyze the failure characteristics of the electric propulsion system in consideration of the difference in the type of failure between the internal diesel engine and the electric propulsion system. The ship's propulsion unit assumed a DC motor and a signal pattern for normal conditions and general failure modes, but the failure record of the electric propulsion device operated on the actual ship was not available, so it generated a failure signal for small electric motor equipment to identify the failure signal. Assuming unbalance, misalignment, and bearing failure, which are the primary failure modes of the ship's electric motor, a failure signal was generated using a "rotator vibration data generator," and the frequency band, size, and phase difference of the measured vibration signal were analyzed to analyze the characteristics of each failure condition. Finally, the characteristics of each failure condition were identified so that the signals according to the failure type could be classified.

• Steel and Composite Structures
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• 제12권1호
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• pp.53-72
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• 2012

In this study, the physically-based failure models for matrix and fibers in compression and tension loading are introduced. For the 3D stress based fiber kinking model a modification is proposed for calculation of the fiber misalignment angle. All of these models are implemented into the finite element code by using the advantage of damage variable and the numerical results are discussed. To investigate the matrix failure model, purely in-plane transverse compression experiments are carried out on the specimens made by Glass/Epoxy to obtain the fracture surface angle and then a comparison is made with the calculated numerical results. Furthermore, shear failure of $({\pm}45)_s$ model is investigated and the obtained numerical results are discussed and compared with available experimental results. Some experiments are also carried out on the woven laminated composites to investigate the fracture pattern in the matrix failure mode and shown that the presented matrix failure model can be used for the woven composites. Finally, the obtained numerical results for stress based fiber kinking model and improved ones (strain based model) are discussed and compared with each other and with the available results. The results show that these models can predict the kink band angle approximately.