• Title/Summary/Keyword: Delayed Failure

Search Result 263, Processing Time 0.024 seconds

Experimental Study on The Bending Collapse Characteristics of Aluminum Rectangular Tubes (알루미늄 사각관의 굽힘붕괴특성에 관한 실험적 고찰)

  • Kim, Chang-Soo;Chung, Tae-Eun;Kang, Shin-You
    • Transactions of Materials Processing
    • /
    • v.7 no.1
    • /
    • pp.49-58
    • /
    • 1998
  • In this paper the bending collapse characteristics of 6XXX series aluminum rectangular tubes were studied with a pure bending collapse test rig which could apply the pure bending moment without imposing additional shear and tensile forces. Under the pure bending moment, there occured three kinds of bending collapse modes-local buckling delayed buckling and tensile failure-depending on the a, b, t (depth width thickness) and material properties. Experimental results are compared with the results of finite element method and other methods.

  • PDF

Multiple Cranial Neuropathy with and Polyradiculoneuropathy as a Delayed Sequelae after of Ethylene Glycol Intoxication (에틸린 글리콜 중독 이후 나타난 지연성 다발성 뇌신경병 및 다발신경뿌리신경병)

  • Kim, Min-Soo;Kim, Sun-Young;Kwon, Jee-Hyun;Kim, Wook-Joo;Jung, Hyun-Chul
    • Annals of Clinical Neurophysiology
    • /
    • v.15 no.2
    • /
    • pp.63-67
    • /
    • 2013
  • Multiple cranial and peripheral neuropathies as a delayed sequellae of ethylene glycol poisoning is a less well known clinical entity and its information about long-term electrophysiological and clinical outcomes is limited. We report a 45-year-old male who presented with acute renal failure and subsequently developed multiple cranial neuropathy, respiratory failure, and flaccid tetraparesis. Through sequential electrophysiological studies, we would like suggest that the main pathophysiology of ethylene glycol-related neuropathy is a demyelinating polyradiculoneuropathy with secondary axonal degeneration.

Failure Time Prediction Capability Comparative Analysis of Software NHPP Reliability Model (소프트웨어 NHPP 신뢰성모형에 대한 고장시간 예측능력 비교분석 연구)

  • Kim, Hee-Cheul;Kim, Kyung-Soo
    • Journal of Digital Convergence
    • /
    • v.13 no.12
    • /
    • pp.143-149
    • /
    • 2015
  • This study aims to analyze the predict capability of some of the popular software NHPP reliability models(Goel-Okumo model, delayed S-shaped reliability model and Rayleigh distribution model). The predict capability analysis will be on two key factors, one pertaining to the degree of fitment on available failure data and the other for its prediction capability. Estimation of parameters for each model was used maximum likelihood estimation using first 80% of the failure data. Comparison of predict capability of models selected by validating against the last 20% of the available failure data. Through this study, findings can be used as priori information for the administrator to analyze the failure of software.

Risk Evaluation of Failure Cause for FMEA under a Weibull Time Delay Model (와이블 지연시간 모형 하에서의 FMEA를 위한 고장원인의 위험평가)

  • Kwon, Hyuck Moo;Lee, Min Koo;Hong, Sung Hoon
    • Journal of the Korean Society of Safety
    • /
    • v.33 no.3
    • /
    • pp.83-91
    • /
    • 2018
  • This paper suggests a weibull time delay model to evaluate failure risks in FMEA(failure modes and effects analysis). Assuming three types of loss functions for delayed time in failure cause detection, the risk of each failure cause is evaluated as its occurring frequency and expected loss. Since the closed form solution of the risk metric cannot be obtained, a statistical computer software R program is used for numerical calculation. When the occurrence and detection times have a common shape parameter, though, some simple results of mathematical derivation are also available. As an enormous quantity of field data becomes available under recent progress of data acquisition system, the proposed risk metric will provide a more practical and reasonable tool for evaluating the risks of failure causes in FMEA.

Behavior of Failure of Agricultural Reservoirs Embankment Reinforced by Geotextile under Overtopping Condition (지오텍스타일로 보강된 농업용 저수지 제체의 붕괴거동)

  • Lee, Dal Won;Noh, Jae Jin
    • Journal of The Korean Society of Agricultural Engineers
    • /
    • v.56 no.2
    • /
    • pp.59-64
    • /
    • 2014
  • In this study, the large scale test was performed to investigate the behavior of failure for the embankment and spillway transitional zone by overtopping. The pore water pressure, earth pressure, settlement and failure pattern of covering embankment with geotextile were compared and analyzed. The pore water pressure showed a small change in the spillway transition zone and core, indicating that the geotextile efficiently reinforced the embankment. The earth pressure decreased the infiltration of the pore water only in inclined cores type to secure local stability. The behavior of failure started from the bottom and gradually progressed upwards. After the intermediate overtopping period (100 min), width and depth of the seepage erosion were very small due to the effect of geotextile which delayed failure. Therefore, the reinforced method by geotxtile was a very effective method to respond to the emergency due to overtopping.

The Evaluation of Accident Management Strategy Involving Operator Action

  • Kim, Jaewhan;Jaejoo Ha
    • Nuclear Engineering and Technology
    • /
    • v.29 no.5
    • /
    • pp.368-374
    • /
    • 1997
  • This paper presents a new approach to the evaluation of an accident management strategy when an operator action is involved. This approach classifies the failure in implementing a given strategy into 4 possible mechanisms, and provides their corresponding quantification methods : 1) the failure to formulate correct intention by operators, 2) the failure to take an adequate action following a correct diagnosis, 3) the failure of a system operation following an adequate action, and 4) the failure due to a delayed action. The proposed method was applied to assess a cavity flooding strategy that uses containment spray system (CSS), and the result shows that the method is more appropriate in evaluating accident management strategies when human action is involved.

  • PDF

Effects of Carbides on Hydrogen-induced Delayed Fracture for the Energy Saving Wire (ESW) (선조철강의 탄화물에 따른 수소지연파괴 거동 분석)

  • Lee, J.B.;Kang, N.H.;Park, J.T.;Ahn, S.T.;Park, Y.D.;Cho, K.M.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • 2009.10a
    • /
    • pp.139-141
    • /
    • 2009
  • This study analyzed the effect of the microstructure and alloying element on hydrogen-induced delayed fracture properties for the Energy Saving Wire (ESW) developed recently. Specimens were produced with a diameter 6.5mm post to the deformation (0, 10, 20 and 30%), followed by injecting the hydrogen. The experimental results by using GAS chromatography showed that the more hydrogen was emitted for high-carbon steel (0.45%C steel and 0.35%C steel) than low-carbon steel(0.2%C-Cr steel and 0.2%C-Cr-Mo steel). And, 0.45%C steel, 0.35%C steel and 0.2%C-Cr-Mo steel exhibited the crack for 30% deformed specimen. The hydrogen emitted was analyzed with the amount, the spheroidization, and the size of the carbides.

  • PDF

Delayed Lateral Row Anchor Failure in Suture Bridge Rotator Cuff Repair: A Report of 3 Cases

  • Jeong, Jae-Jung;Ji, Jong-Hun;Park, Seok-Jae
    • Clinics in Shoulder and Elbow
    • /
    • v.21 no.4
    • /
    • pp.246-251
    • /
    • 2018
  • Compared to single row repair, use of lateral row anchors in suture bridge rotator cuff repair enhances repair strength and increases footprint contact area. If a lateral knotless anchor (push-in design) is inserted into osteoporotic bone, pull-out of the lateral row anchor can developed. However, failures of lateral row anchors have been reported at several months after surgery. In our cases, even though complete cuff healing occurred, delayed pull-out of the lateral row anchor in the suture bridge repair occurred. In comparison to a conventional medial anchor, further biomechanical evaluation of the pull-out force, design, and insertion angle of the lateral anchor is needed in future studies. We report three cases with delayed pull-out of lateral row anchor in suture bridge rotator cuff repair with a literature review.

Hydrogen Delayed Fracture of TRIP Steel by Small Punch Test (소형펀치시험에 의한 TRIP강의 수소 지연파괴 거동)

  • Choi, Jong-Un;Park, Jae-Woo;Kang, Kae-Myung
    • Journal of the Korean institute of surface engineering
    • /
    • v.46 no.1
    • /
    • pp.42-47
    • /
    • 2013
  • The strain-induced phase transformation from austenite to martensite is responsible for the high strength and ductility of TRIP steels. However high strength steels are susceptible to hydrogen embrittlement. This study aimed to evaluate the effects of hydrogen on the behavior of hydrogen delayed fracture in TRIP steel with hydrogen charging conditions. The electrochemical hydrogen charging was conducted at each specimen with varying current density and charging time. The relationship between hydrogen concentration and mechanical properties of TRIP steel was established by SP test and SEM fractography. The maximum loads and displacements of the TRIP steel in SP test decreased with increasing hydrogen charging time. The results of SEM fractography investigation revealed typical brittle mode of failure. Thus it was concluded that hydrogen delayed fracture in TRIP steel result from the diffusion of hydrogen through the ${\alpha}$' phase.