• 제목/요약/키워드: stress transfer

검색결과 1,113건 처리시간 0.02초

플라즈마 용사층에 발생하는 응력해석 (Analysis of thermal stresses developed in plasma sprayed layer)

  • 배강열;김희진
    • Journal of Welding and Joining
    • /
    • 제8권4호
    • /
    • pp.58-68
    • /
    • 1990
  • The formation of thermal stresses by plasma spraying is generally considered as adverse. Therefore, the knowledge of stress distribution in the deposited layer during and after plasma spraying will be of special interest. In this study finite difference heat transfer analysis and finite element stress analysis were carried out to predict the change of stress distribution in the plasma coated layer with the variations of preheat temperature, number of scan, particle size, and bond coat. The results of the numerical analysis were as follows: 1) Transient stresses developed in the coated layer were up to the level of yiedl strength at the temperature. 2) The tensile stresses were developed in the deposited layer and the surface of the substrate, but the compressive stresses were developed in the rest of the substrate. 3) Transient and residual stresses were significantly affected by the preheat temperature. 4) The variations of temperature of powder particle and number of torch scan changed tensile stress distribution, but made no difference on the magnitude of the stresses. 5) Bond coated layer reduced the stree level of deposited layer.

  • PDF

쌍롤형 박판주조공정에서 주조 롤의 열응력 및 열변형 해석 (Analysis of Thermal Stress and Deformation of Casting Roll in Twin Roll Strip Casting Process)

  • 박철민;김완수;박경진
    • 대한기계학회논문집A
    • /
    • 제26권9호
    • /
    • pp.1943-1951
    • /
    • 2002
  • The casting roll design is one of the most important requirements in twin roll strip casting process. Coupled analyses of heat transfer and deformation for the cast roll are carried out by use of the finite element program MARC to examine the thermal stress and deformation. The effects of several factors on thermal stress and deformation are also investigated. The amount of thermal stress increases when the ni thickness increases and when the casting speed and the copper sleeve thickness decrease.

SAS 반응기의 구조 안전성 평가 연구 (Study for Accessment of Structural Stability of SAS Reactor)

  • 이은우;정의동;김윤춘;김종배
    • 한국전산구조공학회:학술대회논문집
    • /
    • 한국전산구조공학회 1995년도 가을 학술발표회 논문집
    • /
    • pp.43-49
    • /
    • 1995
  • Sasol Advanced Synthol Reactor was divided into two chambers by grid plate perforated with diffuser holes. The reactor has high stress level beacuse of membrane stress due to internal pressure, thermal stress due to temperature difference and local stress due to structural discontinuity at the juncture of grid plate and shell. Moreover, geometric nonlinear behaviors may appear in the grid plate because of pressure difference between two chambers. In order to survey the stress level and geometric nonlinear behaviors around grid plate, heat transfer analysis, linear static analysis and geometric nonlinear analysis were performed using NISA II developed by EMRC. This paper demonstrates the result of accessment for linear static and geometric nonlinear analysis under various load combinations.

  • PDF

보건 치과위생사의 이직의도에 영향을 미치는 요인 (Factors associated with turnover intention of public health dental hygienist)

  • 최하나;이지원;조영식
    • 한국치위생학회지
    • /
    • 제11권3호
    • /
    • pp.343-351
    • /
    • 2011
  • Objectives : The aim of this study was to investigate factors associated with turnover intention on public health dental hygienists. Methods : A total 235 public health dental hygienist completed a questionnaire on attitudes related to their job position and sociodemographic status. Results : In total 82.5% of the respondents have experienced a job transfer. Their children and job stress strongly affect turnover intention. Turnover intention was correlated with empowerment, organizational commitment, job satisfaction, burnout and job stress. Using multiple regression analysis, the effects of job stress, children, organizational commitment, job satisfaction, career were satistically significant. Conclusions : The study showed strong relationship between turnover intention and job stress and their children. They had positive attitude for their job position and satisfied with their job. They experienced the stress on their job but had little turnover intention.

Interactions in a homogeneous isotropic modified couple stress thermoelastic solid with multi-dual-phase-lag heat transfer and two temperature

  • Lata, Parveen;Kaur, Harpreet
    • Steel and Composite Structures
    • /
    • 제38권2호
    • /
    • pp.213-221
    • /
    • 2021
  • The objective of this paper is to study the deformation in a homogeneous isotropic thermoelastic solid using modified couple stress theory subjected to ramp-type thermal source with two temperature. The advantage of this theory is the involvement of only one material length scale parameter which can determine the size effects. Laplace and Fourier transform technique is applied to obtain the solutions of the governing equations. The components of displacement, conductive temperature, stress components and couple stress are obtained in the transformed domain. A numerical inversion technique has been used to obtain the solutions in the physical domain. The effect of two temperature is depicted graphically on the resulted quantities. Numerical results show that the proposed model can capture the size effects of microstructures.

의료보험 심사간호사의 업무스트레스와 직무만족도의 관계 (Relationship between Work Stress and lob Satisfaction Experienced by Nurses in Medical Insurance)

  • 최순희;이은주;박민정
    • 기본간호학회지
    • /
    • 제10권3호
    • /
    • pp.354-360
    • /
    • 2003
  • Purpose: This study was done for the purpose of identifying the relationship between work stress and job satisfaction of nurses who were evaluating medical insurance. Method: The participants in the study were 154 nurses who were in charge of evaluating medical insurance in 32 hospitals in Korea. Data were collected for 1 month from April 20 to May 20, 2001. Result: The mean total work stress score was 93.79. In comparison with work stress scores according to the work stress factors, 'work overload'(2.95) had the highest work stress score. The mean total job satisfaction score was 69.56. The total work stress scores did not show significant differences for any of the variables. The total job satisfaction score showed significant differences for the variables of age (F=3.51, p=.01), position (F=3.16, p=.02) and reason for transfer from one department to another (F=3.40, p=.003). Conclusion: The total work stress score showed a inverse correlation(v=-.36, p=.001) with the total job satisfaction score.

  • PDF

복합구조의 철근콘크리트 전이보에 대한 이론적 해석 연구 (A Study on Theoretical Analysis for Reinforced Concrete Transfer Girder of Hybrid Structures)

  • 권기혁;이춘호;김민수;이한선;고동우
    • 한국콘크리트학회:학술대회논문집
    • /
    • 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
    • /
    • pp.623-628
    • /
    • 2000
  • In this paper, the behavior for transfer girder of the upper-wall and lower-frame structures was studied by the nonlinear finite element analysis. It was analyzed and compared with the experimental results. Analysis results showed that failure modes were progressed by a initial diagonal crack in the shear span between the edges of the load and intermediate support plate. The nonlinear finite element analysis could predict deformation, principal stress, ultimate load and concrete crack. Also analysis results showed good agreement the test results.

  • PDF

Spectral Fatigue Analysis for Topside Structure of Offshore Floating Vessel

  • Kim, Dae-Ho;Ahn, Jae-Woo;Park, Sung-Gun;Jun, Seock-Hee;Oh, Yeong-Tae
    • Journal of Advanced Research in Ocean Engineering
    • /
    • 제1권4호
    • /
    • pp.239-251
    • /
    • 2015
  • In this study, a spectral fatigue analysis was performed for the topside structure of an offshore floating vessel. The topside structure was idealized using beam elements in the SACS program. The fatigue analysis was carried out considering the wave and wind loads separately. For the wave-induced fatigue damage calculation, motion RAOs calculated from a direct wave load analysis and regular waves with different periods and unit wave heights were utilized. Then, the member end force transfer functions were generated covering all the loading conditions. Stress response transfer functions at each joint were produced using the specified SCFs and member end force transfer functions. fatigue damages were calculated using the obtained stress ranges, S-N curve, wave spectrum, heading probability of each loading condition, and their corresponding occurrences in the wave scatter diagrams. For the wind induced fatigue damage calculation, a dynamic wind spectral fatigue analysis was performed. First, a dynamic natural frequency analysis was performed to generate the structural dynamic characteristics, including the eigenvalues (natural frequencies), eigenvectors (mode shapes), and mass matrix. To adequately represent the dynamic characteristic of the structure, the number of modes was appropriately determined in the lateral direction. Second, a wind spectral fatigue analysis was performed using the mode shapes and mass data obtained from the previous results. In this analysis, the Weibull distribution of the wind speed occurrence, occurrence probability in each direction, damping coefficient, S-N curves, and SCF of each joint were defined and used. In particular, the wind fatigue damages were calculated under the assumption that the stress ranges followed a Rayleigh distribution. The total fatigue damages were calculated from the combination with wind and wave fatigue damages according to the DNV rule.

반복-수평력을 받는 프리캐스트기둥- RC기초 Anchor 접합부의 내력 실험 연구 (Strength Experimental Study on Precast Column-R.C. Foundation Anchor Joint Subjected to Cyclic Horizontal Loading)

  • 이호;정환목;차병기;변상민
    • 한국공간구조학회논문집
    • /
    • 제9권2호
    • /
    • pp.45-52
    • /
    • 2009
  • 이 논문은 반복-수평력을 받는 프리캐스트 기둥-RC 기초 Anchor 접합부의 반복-수평력에 대한 내력 특성을 규명하기 위함이다. 본 연구는 하부 기초에 프리캐스트 콘크리트 기둥과 기초를 Anchor식으로 접합한 콘크리트 구조체가 정확한 응력전달 경로 및 파괴 메커니즘에 있어서 기존의 콘크리트-강재 연결부와 어떠한 차이가 있는지 제시한다. 반복-수평력 작용하의 철근의 인발력 실험결과는 프리캐스트 기둥-RC 기초 Anchor 시공에 필요한 철근의 최소 필요 삽입 깊이를 제시한다. 또한, 실험을 통해 제시된 응력 전달 경로 및 파괴 메커니즘을 제품별 메뉴얼에 제시되어 있는 메커니즘과 비교, 검토함으로서 접합부의 명확한 응력전달 경로 및 파괴 메커니즘을 시공자의 요구 성능에 맞게 제시한다. 그러므로 본 연구를 통해 프리캐스트 콘크리트 기둥의 정확한 주근의 개수, 공칭직경, 정착 길이 등에 대한 최적의 설계 조건을 제시함으로써, 시공 시 이들에 대한 정확한 데이터를 제공한다.

  • PDF