• 제목/요약/키워드: Safety Stress

검색결과 3,020건 처리시간 0.031초

ASSESSMENT OF POSSIBILITY OF PRIMARY WATER STRESS CORROSION CRACKING OCCURRENCE BASED ON RESIDUAL STRESS ANALYSIS IN PRESSURIZER SAFETY NOZZLE OF NUCLEAR POWER PLANT

  • Lee, Kyoung-Soo;Kim, W.;Lee, Jeong-Geun
    • Nuclear Engineering and Technology
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    • 제44권3호
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    • pp.343-354
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    • 2012
  • Primary water stress corrosion cracking (PWSCC) is a major safety concern in the nuclear power industry worldwide. PWSCC is known to initiate only in the condition in which sufficiently high tensile stress is applied to alloy 600 tube material or alloy 82/182 weld material in pressurized water reactor operating environments. However, it is still uncertain how much tensile stress is re-quired to generate PWSCC or what causes such high tensile stress. This study was performed to pre-dict the magnitude of weld residual stress and operating stress and compare it with previous experi-mental results for PWSCC initiation. For the study, a pressurizer safety nozzle was selected because it is reported to be vulnerable to PWSCC in overseas plants. The assessment was conducted by nu-merical analysis. Before performing stress analysis for plant conditions, a preliminary mock-up ana-lysis was done. The result of the preliminary analysis was validated by residual stress measurement in the mock-up. After verification of the analysis methodology, an analysis under plant conditions was conducted. The analysis results show that the stress level is not high enough to initiate PWSCC. If a plant is properly welded and operated, PWSCC is not likely to occur in the pressurizer safety nozzle.

Verification of Stress Analysis on the Bracket of Bus Bear Chassis

  • Kim, Gyu Sung
    • International journal of advanced smart convergence
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    • 제11권4호
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    • pp.266-272
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    • 2022
  • Structural stress analysis is performed to confirm the safety of the structures before the construction, and stress analysis is performed to evaluate the safety of various components before the ship or vehicle corresponding to the moving structure is manufactured. In this case, the stress analysis work is performed using the stress analysis software of each company. The results of the stress analysis based on the boundary conditions of the applied loads are analyzed to evaluate the safety of the structure, but the results are difficult to verify because most of the stress analysis software possessed by each company is one. In this paper, we were performed the stress analysis of the bracket applied to the bare chassis of the 30-passenger bus under development is performed by HYPERMESH. In order to verify this, the stress analysis is performed using ANSA/META under the same boundary condition. The stress analysis results of ANSA/META and HYPERMESH showed that they had the same stress distribution and the maximum stress occurred at the same location. Taken together, the results of stress analysis using HYPERMESH were reliable.

비행안전 위해(Hazard)요인이 조종사의 안전행동에 미치는 영향 (Effects of Job Stress and Hazard Factors on Pilot Safety Behavior)

  • 이동렬;김현덕
    • 한국항행학회논문지
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    • 제28권1호
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    • pp.87-94
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    • 2024
  • 항공산업의 발전에도 불구하고 조종사의 인적오류에 의한 항공기 사고는 지속해서 발생하고 있다. 인적오류에 의한 항공기 사고의 원인은 비행안전을 저해하는 위해(hazard) 요인을 사전에 제거하지 못해 사고로 이어지는 것이다. 본 연구는 국내 항공사에 근무하는 운항승무원과 일반항공 (general aviation)의 조종사를 대상으로, 비행안전을 위협하는 여러 가지 위해 요인 중에서 조종사에게 심리적, 신체적으로 영향을 미치는 직무스트레스와 피로, 불안감이 안전행동에는 어떠한 영향을 미치는지 살펴보았다. 아울러 직무스트레스와 안전행동의 간에 안전문화의 매개효과를 확인하기 위한 실증분석을 실시하였다. 연구 결과에 의하면 직무스트레스는 조종사의 안전행동에 직접적인 영향을 줄 뿐만이 아니라 안전분위기, 보고문화와 같은 항공사의 안전문화에도 영향을 미친다는 것이다. 이러한 조종사의 직무스트레스와 안전문화, 안전행동간의 상관관계를 통해 안전관리시스템의 성과를 제고하고자 한다.

안전/보건관리자의 외상 사건 경험이 외상 후 스트레스 장애에 미치는 영향 -직무스트레스를 통한 사회적지지의 조절된 매개효과- (A Study on the Effects of Trauma Case Experience on PTSD of Safety/Health Manager's -The Moderated Mediation Effect of Social Support through Job Stress-)

  • 심재범;이미은
    • 한국산업보건학회지
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    • 제31권1호
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    • pp.38-49
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    • 2021
  • Objectives: This study was conducted to analyze the impact of safety/health managers' experience of trauma case on their post traumatic stress disorder and the mediation effects of job stress and the moderated mediation effects of social support. Method: Using a structured questionnaire, data were collected from 241 workplace safety/health managers with experience in trauma case. The collected data were analyzed using SPSS(IBM. Ver.26.0) and verified through SPSS PROCESS Macro (Ver. 3.4). Results: The trauma case experience and the job stress, which is a mediation variable, had a statistically significant positive effect on post-traumatic stress disorder, and the job stress had a positive mediation effect in the relationship between the trauma case experience and post-traumatic stress disorder. Social support had a statistically significant negative moderation effect in the relationship between the trauma case experience and job stress; social support had a moderated mediation effect on the indirect effect of a job stress on the post-traumatic effect through a trauma case experience. Conclusion: The above findings suggest that work-related job stress management is important in order to reduce safety/health managers' post-traumatic stress disorder caused by the experience of trauma case, and that social support is essential to reduce the job stress, which can later be used as a basis for further studies.

간호·간병통합서비스 병동 간호사의 환자안전문화인식, 감정노동, 직무스트레스가 환자안전간호활동에 미치는 영향 (Effects of Awareness of Patient Safety Culture, Emotional Labor and Job Stress on Patient Safety Nursing Activities by Comprehensive Nursing Care Medical Service Ward Nurses)

  • 최효정;이윤미;박효진
    • 중환자간호학회지
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    • 제14권3호
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    • pp.87-98
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    • 2021
  • Purpose : This study aimed to examine the effects of the awareness of patient safety culture, emotional labor, and job stress on patient safety nursing activities by comprehensive nursing care medical service ward nurses. Methods : The participants were 112 nurses from the comprehensive nursing care service wards from six hospitals. Data were collected using structured questionnaires and analyzed using a t-test, ANOVA, Scheffé test, Pearson correlation coefficients, and multiple regression analysis using SPSS version 20.0. Results : The factors that significantly influenced patient safety nursing activities in the comprehensive nursing care medical service ward nurses included job stress (𝛽=-0.18, p<.032) and awareness of patient safety culture (𝛽=0.54, p<.001). The explanatory power of these factors was 31.0% (F=13.43, p<.001). Conclusion : This study showed that the factors that influenced patient safety management activities of comprehensive nursing care medical service ward nurses included job stress and awareness of patient safety culture.

철도레일의 파괴 및 피로에 대한 안전도평가 및 잔류수명계산 (The Evaluation of Safety and Remaining Life on Fracture and Fatigue in Rail Steel)

  • 박용걸
    • 한국안전학회지
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    • 제10권2호
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    • pp.120-128
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    • 1995
  • The fatigue failure of rail is a principal source of derailment accidents. The reduction of fatigue failures can be achieved by Intensive track maintenance and periodic safety assessments for the railway. For the safety assessments, it is required to have more accurate knowledge for fatigue behavior such as the crack initiation, propagation, crack growth rate and the remaining service life in rail. In this paper, the mean stress effects for the fatigue behavior of rail steel are studied. For this study, the fatigue test is conducted and some equations for fatigue evaluation are applied and compared. From the results, we can see that the fatigue crack growth rate is the more increased as the men stress Is the more increased, the mean stress effect is represented well by the combination of stress intensity factor range and maximum stress intensity factor and Crooker and Range's equation represented by ${\Delta}K, K_{max}$ is the best fit for fatigue evaluation and safety assessment of rail.

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파일의 시공오차를 고려한 스태빙시스템의 구조안전성 평가 (Structural Safety Evaluation of Stabbing System for Pre-Piling Jacket Substructure Considering Pile Construction Errors)

  • 오영철;류재용;이대용
    • 풍력에너지저널
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    • 제14권3호
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    • pp.109-119
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    • 2023
  • A structural safety evaluation was conducted for the stabbing system for the pre-piling jacket substructure currently being developed in South Korea, considering pile construction errors due to its lateral movement that may occur during construction in the ocean. Based on (1) the maximum stress generated by the stabbing system, (2) the maximum rotational displacement of the guide cone, and (3) the maximum stress generated by the horizontal hydraulic pressure cylinder, the structural safety of the stabbing system was examined under the initial loading condition and three possible load combinations during its construction. In order to evaluate the structural safety of the stabbing system, a concept of stress safety factor (= Yield stress / Max. Von-Mises stress) was used. It was found that the stabbing system considered in this study has a sufficient margin of safety.

비행 스트레스가 직무 만족도와 안전문화에 미치는 영향 : 항공사 및 직급별 조절된 매개효과 (The Effect of Flight Stress on Job Satisfaction and Safety Culture: Moderator Effect by Airlines and Rank)

  • 유병선;고강민
    • 한국항행학회논문지
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    • 제28권1호
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    • pp.44-50
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    • 2024
  • 본 연구는 국내 민간 항공사 조종사 193명을 대상으로 비행 스트레스가 직무 만족도 및 안전문화에 미치는 영향을 분석하였다. 분석 결과, 비행 스트레스는 직무 만족도에 부정적 영향을 미쳤으며, 직무 만족도가 낮은 조종사는 안전문화 인식도 낮게 나타났다. 특히, 항공사와 조종사의 직급에 따라 비행 스트레스가 직무 만족도와 안전문화에 미치는 영향에 차이를 보였다. 이는 항공사와 조종사 직급별로 맞춤형 스트레스 관리 프로그램 개발의 필요성을 시사한다. 연구는 항공 산업의 안전 문화 강화를 위해 조종사의 스트레스 관리와 직무 만족도 향상이 중요함을 강조한다. 또한, 항공사는 조종사의 스트레스를 감소시키고, 직무 만족도를 높여 안전문화를 강화하는 전략을 개발해야 한다. 본 연구 결과는 항공산업에서 조종사들의 스트레스 관리와 안전문화 강화를 위한 방안 모색에 유용한 기초 자료로 활용하기 위함이다.

Experimental study on seepage characteristics of large size rock specimens under three-dimensional stress

  • Sun, Wenbin;Xue, Yanchao;Yin, Liming;Zhang, Junming
    • Geomechanics and Engineering
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    • 제18권6호
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    • pp.567-574
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    • 2019
  • In order to study the effect of stress and water pressure on the permeability of fractured rock mass under three-dimensional stress conditions, a single fracture triaxial stress-seepage coupling model was established; By using the stress-seepage coupling true triaxial test system, large-scale rock specimens were taken as the research object to carry out the coupling test of stress and seepage, the fitting formula of permeability coefficient was obtained. The influence of three-dimensional stress and water pressure on the permeability coefficient of fractured rock mass was discussed. The results show that the three-dimensional stress and water pressure have a significant effect on the fracture permeability coefficient, showing a negative exponential relationship. Under certain water pressure conditions, the permeability coefficient decreases with the increase of the three-dimensional stress, and the normal principal stress plays a dominant role in the permeability. Under certain stress conditions, the permeability coefficient increases when the water pressure increases. Further analysis shows that when the gob floor rock mass is changed from high stress to unloading state, the seepage characteristics of the cracked channels will be evidently strengthened.

Theoretical and numerical analysis of the influence of initial stress gradient on wave propagations

  • Tao, Ming;Chen, Zhenghong;Li, Xibing;Zhao, Huatao;Yin, TuBing
    • Geomechanics and Engineering
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    • 제10권3호
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    • pp.285-296
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    • 2016
  • The investigation of stress wave propagation in a medium with initial stress has very important application in the field of engineering. However, the previous research less consider the influence of initial stress gradient on wave propagation. In the present paper, the governing equation of wave propagation in elastic continuum material with inhomogeneous initial stress is derived, which indicated that the inhomogeneous initial stress changed the governing equation of wave propagation. Additionally, the definite problem of wave propagation in material with initial stress gradient is verified by using mathematical physics method. Based on the definite problem, the elastic displacement-time relationship of wave propagation is explored, which indicated that the inhomogeneous initial stress changed waveform and relationship of displacement-time histories. Furthermore, the spall process of blasting wave propagation from underground to earth surface is simulated by using LS-DYNA.