• Title/Summary/Keyword: behavior of failure

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The Relationship between Parental Attribution and Self-Perception in Parenting Roles to Parenting Success or Failure Situations among Mothers of Toddlers (걸음마기 영아 어머니의 양육수행 성공여부에 따른 양육행동 귀인과 부모역할 자기인식의 관계)

  • Han, Sae-Young;Lee, Eun Gyoung
    • Korean Journal of Childcare and Education
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    • v.12 no.3
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    • pp.21-39
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    • 2016
  • The purpose of this study was to examine the relationship between parental attribution and self-perception in parenting roles according to parenting success or failure situations. A total of 138 mothers who have toddlers in Seoul and other big cities in Korea completed questionnaires, and data were analyzed by paired t-test, Pearson's correlation coefficient, Fisher's Z score, and multi-regression. The results are as follows: First, mothers in parenting success situations showed higher parental attribution than mothers in parenting failure situations. Second, correlations between parental attribution and self-perception in parenting roles turned out to be significantly different between parenting success situations and failure situations. Third, both internal attribution such as ability and effort, and external attribution such as child behavior and task difficulty, significantly predicted self-perception in parenting roles including equilibrium feeling, competence, satisfaction and parenting investment, especially in parenting failure situations. The implications of the difference in parental attribution between parenting success and failure situations have been discussed.

Failure Mode and Strength of Unidirectional Composite Single Lap Bonded Joints II. Failure Prediction (일방향 복합재료 Single Lap 접합 조인트의 파손 모드 및 파손 강도 II. 파손 예측)

  • Yi Young-Moo;Kim Chun-Gon;Kim Kwang-Soo
    • Composites Research
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    • v.18 no.1
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    • pp.1-9
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    • 2005
  • A methodology is presented for the failure prediction of composite single-lap bonded joints considering both of composite adherend failure and bondline failure. An elastic-perfectly plastic model of adhesive and a delamination failure criterion are used in the methodology. The failure predictions have been performed using finite element method and the proposed methodology. The failure prediction results such as failure mode and strength have very good agreements with the test results of joint specimens with various bonding methods and parameters. The influence of variations in the effective strength (that is, adhesion performance) and plastic behavior of adhesive on the failure characteristics of composite bonded Joints are investigated numerically. The numerical results show that optimal joint strength is archived when adhesive and delamination failure occur in the same time.

Flexural Behavior of Damaged RC Beams Repaired with Epoxy Mortar System (에폭시 모르터로 보수한 손상을 입은 RC 보의 휨 거동)

  • 조하나;신영수;홍건호;정혜교
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.04a
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    • pp.762-767
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    • 1999
  • This paper presents an experimental study on flexural behavior of damaged RC beams repaired with epoxy mortar system. The main test variables are repair length and depth. A series of 7 specimens was tested to show the corresponding effect of each variables on maximum load capacity, load-deflection relationship, and failure mode. The results of this study shows that flexural behavior of repaired RC beams changes as the repair length and depth is getting longer and deeper, so that the tension strength of repairing materials should be considered in the courses of repair design.

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Rate-dependent Viscoplastic-Damage Model of Concrete under Cyclic Loading (반복하중을 받는 콘크리트의 재하속도 의존 점소성-손상 모델)

  • 송하원;임현우;김인순
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.10a
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    • pp.468-473
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    • 1998
  • The objective of this paper is to develop a consistent algorithm for the finite element analysis for behavior of concrete under cyclic loading using viscoplastic-damage model. For modeling the behavior of concrete under cyclic loading, consistent algorithms of rate-dependent viscoplastic-damage are employed with a Willam-Warnke 5-parameter failure criterion which can consider the softening behavior of concrete and consistent tangent moduli are derived. Using finite element program implemented with the developed algorithms, the algorithms are verified and the behaviors of concrete under cylic loading are simulated and compared with experimental data.

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Buckling and Postbuckling Behavior of Stiffened Laminated Composite Panels (보강된 복합적층 판넬의 좌굴 및 좌굴후 거동 연구)

  • Lee, In-Cheol;Gyeong, U-Min;Gong, Cheol-Won;Hong, Chang-Seon;Kim, Cheon-Gon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.10
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    • pp.3199-3210
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    • 1996
  • The buckling and postbuckling behaviors were sutdied analytically and experimentally for stiffened laminated composite panels under compression loading. The panels with I-, blade, -and hat-shapeed stiffeners were investigated. In the analysis, the stiffened panels were anlyzed using the nonlinear finite element method combined with an improved arc-length method. The progressive failure analysis was done by adopting the maximum stress criterion and complete unloading failure model. The effects of the fiber angles were investigated on the buckling and postbuckling behaviors. In the experiment, the web and the lower cap of each stiffener were formed by the continuous lay-up of the skin for cocuring the stiffened panels. Therefore, the separation between stiffener and skin was not found in the junction part even after postbuckling ultimate load and the stiffened panels had excellent postbuckling load carrying capacity. A shadow moire thchnique was used to monitor the out-of-plane deformations of the panels. The piezoelectric films were attached to the panels to get the failure characteristics of the panel. The analytical results on the buckling load, postbuckling ultimate load, and failure pattern showed good agreement with the experimental results.

Experimental Study on Failure Behavior of Steel Members and Elements under Very Low Load-Cycles (극저하중(極低荷重)사이클을 받는 강부재(鋼部材) 및 요소(要素)의 파괴거동(破壞擧動)에 관한 실험적(實驗的) 연구(硏究))

  • Park, Yeon Soo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.14 no.2
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    • pp.257-268
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    • 1994
  • An experimental study was carried out to elicit important factors causing cracks and rupture of steel members and their elements under imposed large repeated deformations, and of the quantitative relationships among the important physical factors leading to failure. Each of twenty-eight angles and nine thin-plates served as the specimen and was subjected to repeated axial load after undergoing inelastic buckling. Particular attention was paid to the effects of loading pattern, failure mode and cross-sectional shape on the very-low-cycle failure behavior under loading repetitions of the order of a few to twenty. The experimental results show that energy dissipation capacity depends heavily on the entire history of loading, the failure mode, the slenderness ratio and the width-to-thickness ratio. No simple quantitative relations were observed between the initiation of the visible cracks or rupture and the energy dissipation capacity. The maximum values of residual "net" strains are found to range from 25% to 40%, independent of the test parameters.

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Instability Analysis of Unsaturated Soil Slope Considering Wet Condition (습윤상태를 고려한 불포화 토사사면의 불안정성 해석)

  • Kim, Yong Min;Kim, Jaehong
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.4
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    • pp.1489-1498
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    • 2013
  • The monolithically coupled finite element analysis for a deformable unsaturated soil slope is performed to investigate the effect of antecedent rainfall which is assumed by initial conditions varying degree of saturation (36, 51, 77%) in finite element analysis. The distributions of matric suction and deformation on slope surface obtained from numerical simulation show the instability of antecedent rainfall-induced unsaturated soil slope. Moreover, the numerical analysis using Drucker-Prager model can be checked if a soil slope has reached failure (trial failure criterion $f^{tr}$ >0, plastic behavior) or not (trial failure criterion $f^{tr}$ < 0, elastic behavior). It is found that displacement of slope surface layer increases and the matric suction on soil slope decreases with an increase of initial degree of saturation by antecedent rainfall. Especially, the matric suction of the soil slope in dry condition (S=36%) rapidly decreases rather than that in wet condition (S=51%) at the same rainfall duration. The results of the trial failure criterion ($f^{tr}$ > 0) show slope instability in the toe region and surface of the slopes.

Experimental and Analytical studies on Failure Behavior of Stud Shear Connectors in CFT Structures (CFT 구조에 적용된 스터드 전단연결재의 파괴 거동에 대한 실험 및 해석적 연구)

  • Lee, Sangyoon
    • Journal of the Society of Disaster Information
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    • v.9 no.4
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    • pp.400-412
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    • 2013
  • For the composite behavior of steel tube and inner concrete, the shear connectors should be applied to the CFT structures. However, the present design codes don't provide the design criteria that can be applied on shear connectors in the CFT structures typically filled with plain concrete. This study has been carried out to propose design criteria (shear strength and resistance factor) for the stud shear connectors in CFT structures. Experimental tests using the push-out specimens with the plain concrete blocks and finite element analysis were conducted for the purpose of verifying the main failure mode to propose the shear strength of studs in CFT structures. From the results of this study, the main failure mode of studs in CFT structures is splitting crack of concrete and this failure mode reduces shear strength of studs in CFT structures relatively to those embedded in RC blocks.

The Effects of Health, Cognition, and Safety Climate on Safety Behavior and Accidents: Focused on Train Drivers (건강, 인지 및 안전풍토가 안전행동과 사고에 미치는 영향: 철도기관사를 중심으로)

  • Lee, Yong Man;Shin, Tack Hyun;Park, Min Kyu
    • Journal of the Korean Society for Railway
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    • v.16 no.4
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    • pp.331-339
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    • 2013
  • This study highlights the theme of human error emerging as a critical issue in the railroad industry, conducting exploratory research on the effects of health, cognition, and safety climates on safety behavior and accidents using an empirical method. The statistical results based on questionnaires received from 204 train drivers indicate that psychological fatigue, cognitive failure, and internal locus of control as individual variables and CEO philosophy and behavior of immediate boss as organizational variables have significant relationships with safety behavior, while cognitive failure, CEO philosophy, behavior of immediate boss, and education were found to be significant variables with respect to accidents. Furthermore, unsafe behavior such as mistakes and violations showed negative effects on near misses and responsibility accidents, respectively. Based on these results, effective alternatives and countermeasures needed to mitigate human error were posited.

Behavior of failure of agricultural reservoir embankment due to overtopping (월류에 의한 저수지 제체의 붕괴 거동)

  • Lee, Dal-Won;Noh, Jae-Jin
    • Korean Journal of Agricultural Science
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    • v.39 no.3
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    • pp.427-439
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    • 2012
  • In this study, an experiment with large-scale model was performed according to raising embankment in order to investigate the behaviour of failure due to overtopping. The pore water pressure, earth pressure and settlement by high water level, a rapid drawdown and overtopping were compared and analyzed. Also, seepage analysis and slope stability analysis were performed for steady state and transient conditions. The pore water pressure and earth pressure for inclined core type showed high value at the base of the core, but they showed no infiltration by leakage. The pore water pressure and earth pressure by overtopping increased at the upstream slope and core, it is considered a useful data that can accurately estimate the possibility of failure of the reservoir. The behavior of failure due to overtopping was gradually enlarged towards the downstream slope from reservoir crest, and the inclined core after the raising embankment was influenced significantly to prevent the reservoir failure. The pore water pressure distribution for steady state and transient condition showed positive (+) pore water pressure on the upstream slope, it was gradually changed negative (-) pore water pressure on the downstream slope. The pore water pressure by overtopping showed a larger than the high water level at the downstream slope, it was likely to be the piping phenomenon because the hydraulic gradients showed largely at the inclined core and reservoir crest. The safety factor showed high at the steady state, and transient conditions did not show differences depending on the rapid drawdown.