• 제목/요약/키워드: Stress evaluation

검색결과 3,240건 처리시간 0.03초

응력특이성을 고려한 세라믹/금속 접합재의 정적강도평가 (Evaluation of Static Strength on Ceramic /Metal Bonded Joints Considering Stress Singularity)

  • 김기성
    • 한국생산제조학회지
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    • 제6권1호
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    • pp.59-68
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    • 1997
  • Recently, the cases of using bonded dissimiliar materials which have each of the different components tend to increase for the purpose of developing new materials and using the special objects in the field of industry. Among the cases the strength evaluation of the joining materials of vehicle engine and the structural materials with ceramic/metal bonded joints becomes more important. But the residual stress occurs, because the joining of ceramics and metals is performed in extremely high temperature. It becomes a dominant cause to reduce the strength of the ceramic/metal bonded joints. In this paper, strength evaluation method of ceramic/metal bonded joints considering stress singularity was investigated by boundary element method and 4-point bending test. An advanced method of quantitative strength evaluation for ceramin/metal bonded joints is to be suggested.

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외상성 뇌손상이후 발생하는 외상후 스트레스장애와 급성스트레스 장애의 평가 및 치료 (The Evaluation and Treatment of Post-Traumatic Stress Disorder and Acute Stress Disorder After Traumatic Brain Injury)

  • 박기창
    • 생물정신의학
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    • 제2권2호
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    • pp.193-204
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    • 1995
  • Traumatic brain injury(TBI) used to be developed after a severe traumatic event. Therefore TBI usually induces acute or chronic stress reaction. I reviewed the concept, epidemiology, biological or psychosocial etiology, diagnosis and treatment of post-traumatic stress disorder (PTSD), and discussed about PTSD or stress reaction after TBI. Early evaluation and management of stress reaction after TBI are important.

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응력특이성을 고려한 접착이음의 강도평가 방법 (Evaluation Method of Bonded Strength Considering Stress Singularity in Adhesively Bonded Joints)

  • 정남용
    • 한국생산제조학회지
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    • 제7권1호
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    • pp.58-68
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    • 1998
  • Advantages of adhesively bonded joints and techniques of weight reduction have led to increasing use of structural adhesives such as LSI(large scale integration) package, automobile, aircraft in the various industries. In spite of such wide applications of adhesively bonded joints, the evaluation method of bonding strength has not been established. Stress singularity occurs at the interface edges of adhesively bonded joints and it is required to analyze it. In this paper, the stress singularity using 2-dimensional elastic boundary element method (BEM) with the changes of the lap length and adhesive for single lap joint was analyzed, and experiments of strength evaluation were carried out. As the results, the evaluating method of bonding strength considering stress singularity at interface edges of adhesively bonded joints and stress intensity factor of interface crack have been proposed in static and fatigue test.

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미디어 관여도가 외모평가, 외모스트레스, 외모관리행동에 미치는 영향 (Media Involvement on Appearance Evaluation, Appearance Stress, and Appearance Management Behavior)

  • 전지현;이미숙
    • 한국의류학회지
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    • 제38권4호
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    • pp.518-527
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    • 2014
  • This study examined the effect of media involvement on appearance evaluation, appearance stress, and appearance management behavior. Data were collected from 315 female university students in Daejeon and Chungnam from May to June 2013. Data were analyzed by descriptive statistics, t-test, path analysis using the SPSS-WIN 20.0, AMOS 20.0 program. The results of this study were as follows. First, media involvement were classified into low and high groups. There were significant differences in appearance evaluation by level of involvement. The low group of media involvement indicated a more positive appearance evaluation than the high group. Second, there were significant differences in the appearance management behavior by level of involvement. Third, media involvement directly affected appearance evaluation and appearance management behavior. Appearance evaluation affected appearance stress and appearance management behavior. This study verified the structural relationship of media involvement, appearance stress, and appearance management behavior as outward behavior variables.

European Approaches to Work-Related Stress: A Critical Review on Risk Evaluation

  • Zoni, Silvia;Lucchini, Roberto G.
    • Safety and Health at Work
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    • 제3권1호
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    • pp.43-49
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    • 2012
  • In recent years, various international organizations have raised awareness regarding psychosocial risks and work-related stress. European stakeholders have also taken action on these issues by producing important documents, such as position papers and government regulations, which are reviewed in this article. In particular, 4 European models that have been developed for the assessment and management of work-related stress are considered here. Although important advances have been made in the understanding of work-related stress, there are still gaps in the translation of this knowledge into effective practice at the enterprise level. There are additional problems regarding the methodology in the evaluation of work-related stress. The European models described in this article are based on holistic, global and participatory approaches, where the active role of and involvement of workers are always emphasized. The limitations of these models are in the lack of clarity on preventive intervention and, for two of them, the lack of instrument standardization for risk evaluation. The comparison among the European models to approach work-related stress, although with limitations and socio-cultural differences, offers the possibility for the development of a social dialogue that is important in defining the correct and practical methodology for work stress evaluation and prevention.

피로설계 및 평가를 위한 3차원 유한요소 응력해석에 관한 고찰;모터구동밸브를 이용한 사례연구 (3-D Finite Element Stress Analysis for Fatigue Design and Evaluation;A Parametric Study of MOV(Motor Operated Valve))

  • 김형근;이상민;장윤석;최재붕;김영진;김윤재
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 추계학술대회
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    • pp.142-147
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    • 2004
  • In this paper, a new procedure is proposed to accomplish the primary plus secondary stress(P+Q) at the 'structural element' instead of 'transition element'. For the P+Q evaluation, the calculated stresses by FEA are linearized along a stress classification line to extract the stress category, then the stress intensity is calculated to compare with the $3S_{m}$ limit. Also, in this paper, the 'design by analysis' criteria, adopted fundamental concepts and a new approach to calculate $K_{e}$ factors are explained. The new procedure combined with 3-D FEA has been applied to motor operated valve in order to the over conservatism and the rack of margin. The evaluation results show a good applicability and can be utilized for fatigue life evaluation by using P+Q.

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Evaluation Method of Hairstyling Materials and its Application to Cosmetic Preparations

  • Abe, Hidetoshi;Iida, Ichiro;Someya, Takao
    • 대한화장품학회:학술대회논문집
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    • 대한화장품학회 2003년도 IFSCC Conference Proceeding Book I
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    • pp.1-12
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    • 2003
  • Instead of sensory evaluation, we designed an evaluation method of the setting function of hairstyling products, based on an original theory focusing on changes in bending stress observed when a load with continuous bending is applied to human hair. Specifically, we developed a device to measure bending stress to quickly and objectively evaluate the condition of human hair, particularly its dynamic properties such as the setting function, following the application of hairstyling products. This device generates a load with continuous bending while applying a pendulum motion to a hair tress, one end of which is anchored. The setting function and holding power of resins of various molecular weight and ionic properties were evaluated using this device. The results demonstrated a close correlation with those obtained by experts' sensory evaluation. The evaluation results of bending stress and holding rate confirmed that the combined use of two different resins could improve the function of setting preparations. Evaluation using this device was able to substitute for sensory evaluation, and offers quick objective evaluation and detection of changes in the holding power of hairstyling products over time. We conclude that evaluation using this device is a promising new method.

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ASME BPVC Section XI Appendix L의 결함허용평가에 따른 허용운전주기 민감도 분석 (Sensitivity Analysis for Allowable Operating Period Based on the Flaw Tolerance Evaluation of ASME BPVC Section XI Appendix L)

  • 오창식;조두호;정명조
    • 한국압력기기공학회 논문집
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    • 제17권2호
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    • pp.126-136
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    • 2021
  • During operation of nuclear power plants, the fatigue assessment should be conducted repeatedly, considering changes of operating environments. For the case that cumulative usage factors (CUFs) may exceed the acceptance limit, flaw tolerance evaluation can be an alternative method to meet the regulatory requirements. In this respect, this paper analyzes the effects of the input variables for flaw tolerance evaluation based on ASME BPVC Section XI Appendix L. The reference analysis is performed for the example problem in NUREG/CR-6934. Then effects of the crack orientation, stress intensity factor solutions, thermal stress profiles, fatigue stress decomposition and fatigue crack growth curves are considered for the sensitivity analysis. The results show that the stress analysis considering the actual environment plays a crucial role in flaw tolerance evaluation.

구속효과를 고려한 원자로 압력 용기의 파괴거동 예측 (Evaluation of the Crack Tip Fracture Behavior Considering Constraint Effects in the Reactor Pressure Vessel)

  • 김진수;최재붕;김영진
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2000년도 춘계학술대회논문집A
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    • pp.908-913
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    • 2000
  • In the process of integrity evaluation for nuclear power plant components, a series of fracture mechanics evaluation on surface cracks in reactor pressure vessel(RPV) must be conducted. These fracture mechanics evaluations are based on stress intensity factor, K. However, under pressurized thermal shock(PTS) conditions, the combination of thermal and mechanical stress by steep temperature gradient and internal pressure causes considerably high tensile stress at the inside of RPV wall. Besides, the internal pressure during the normal operation produces high tensile stress at the RPV wall. As a result cracks on inner surface of RPVs may experience elastic-plastic behavior which can be explained with J-integral. In such a case, however, J-integral may possibly lose its validity due to constraint effect. In this paper, in order to verify the suitability of J-integral, two dimensional finite element analyses were applied for various surface crack. Total of 18 crack geometries were analyzed, and Q stresses were obtained by comparing resulting HRR stress distribution with corresponding actual stress distributions. In conclusion, HRR stress fields were found to overestimate the actual crack-tin stress field due to constraint effect.

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한의 난임 치료의 심신 기능 개선 평가를 위한 표준 평가도구 개발에 대한 임상 한의사 대상 기초 설문조사 (A Basic Survey of Korean Medicine Doctors to Develop Standard Evaluation Tools for Evaluating of Mental and Physical Function Improvement following Korean Medicine Infertility Treatment)

  • 이수진;김동일;최수지
    • 대한한방부인과학회지
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    • 제35권4호
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    • pp.105-120
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    • 2022
  • Objectives: The purpose of this study is to investigate the perception of Korean Medicine (KM) doctors toward infertility treatment evaluation tools and develop a standard evaluation tool for mental and physical function improvement following Korean medicine treatment. Methods: An online survey (Moaform) was conducted, and responses were analyzed for members of the Society of Korean Medicine Obstetrics and Gynecology and KM doctors who participated in the 2021-2022 traditional Korean medicine treatment infertility support program in Gyeonggi-do. Results: In fertility treatment, the most effective indicators that KM doctors wanted to evaluate other than pregnancy and childbirth were reproductive health indicators, overall health improvement, and stress improvement (33.1%, 21.2%, 18.9%). Furthermore, 45.1% of the respondents had experience using the presented infertility stress evaluation tools. For each evaluation tool, 52.1% and 54.6% of the respondents answered that it 'does not reflect the changing circumstances of the times' and that there were 'too many questions'. As for the developing a standard evaluation tool for infertility treatment in KM, KM doctors expected a simple and clear tool focusing on the pregnancy rate. They also wanted the tool to include a reproductive health index, overall function improvement and stress improvements. Conclusions: The survey confirmed the need to evaluate indicators for reproductive health, mental health, and infertility stress in addition to pregnancy rate to assess the effectiveness of KM infertility treatment. It also confirms the necessity of developing an infertility stress evaluation tool with simplified questions that reflects the changing time.