• 한국문헌정보학회지
• /
• 제57권3호
• /
• pp.27-48
• /
• 2023

본 연구는 2023년 1월부터 2023년 3월까지 독서아카데미에 참여한 서울특별시 k구에 근무하는 공무원을 대상으로 하여 진행되었다. 이 연구의 목적은 직무스트레스가 지방공무원의 직무만족과 생활만족에 미치는 영향을 파악하는 것이다. 총 300부의 설문지를 회수하고 다중회귀분석을 수행하여 얻은 결과는 다음과 같다. 첫째, 독서아카데미에 참여한 지방공무원들의 직무스트레스 분석 결과, 직무스트레스의 하위 요인 중 보상이 부적절할수록 이직 의도가 높아졌다. 또한 참여자들은 여러 가지 업무를 동시에 처리하고 시간에 쫓기며 일하는 상황 등에서 직무스트레스를 느끼며, 근무조건이나 상황에 바람직하지 못한 변화, 조직개편에 대한 불안감 등이 직무스트레스에 영향을 미치는 것으로 나타났다. 특히 보상이 적절하다고 인식하지 않을 때 이직 의도가 높은 것으로 드러났다. 둘째, 독서아카데미에 참여한 지방공무원들의 직무스트레스로 인해 근무조건이나 상황에 바람직하지 못한 변화, 조직개편에 대한 불안감, 일관성 없는 업무지시, 성별 차별, 권위적인 조직 분위기 등이 생활만족에 부정적인 영향을 미치는 것으로 확인되었다. 셋째, 독서아카데미에 참여한 지방공무원들의 직무만족이 생활만족에 미치는 영향을 분석한 결과, 직무만족의 이직 의도와 보수수준이 정서적 만족에 긍정적인 영향을 미치는 반면, 직무 자체와 대인관계는 정서적 만족에 부정적인 영향을 미쳤다. 또한, 직무 자체와 보수수준이 신체적 만족에 긍정적인 영향을 미치며, 사회적 만족에도 긍정적인 영향을 미치지만, 이직 의도는 부정적인 영향을 미치는 것으로 나타났다.

• 산업기술연구
• /
• 제20권A호
• /
• pp.149-158
• /
• 2000

After measuring actual stress by two measurements(Dynamic Strain Meter, Histogram Recorder) on truss rail road bridge, we could perform time history analysis by 3-D beam element method on modelling bridge. And then, after analyzing bridge structure in static by 3-D modelling, we estimated degree of fatigue damage in main member, secondary member of tie zone, cutting area of base metal cross section for confirming the result. In case that the simulated stress is carried out on modeling bridge, most of those simulation mainly is performed by main members. But in real bridge fatigue damage problems generally caused by junctions, connections, joints in which especially local stress is activated. Therefore, in this paper actual stress on critical area was estimated through the analysis result by simulation. With this study, we can estimate the degree of fatigue damage from a safety point of view and comparative accuracy.

• Journal of Mechanical Science and Technology
• /
• 제14권9호
• /
• pp.935-946
• /
• 2000

Elastic-plastic stress analysis has been performed to evaluate the fatigue life of an autofrettaged pressure vessel containing cross-bores subjected to pulsating internal pressure of 200 MPa. Finite element analyses were used to calculate the residual and operating stress distributions of the pressure vessel due to the autofrettage process and pulsating internal pressure, respectively. Theoretical stress concentration factors of 3.06, 2.58, and 2.64 were obtained at the cross-bore of the pressure vessel due to internal pressure, 50%, and 100% autofrettage loadings, respectively. Local stresses and local strains determined from the elastic-plastic finite element analysis were employed to calculate the failure location and fatigue life of the pressure vessel with radial cross-bores, incorporating the low-cycle fatigue properties of the pressure vessel steel and fatigue damage parameters. Increase in the amount of overstrain by autofrettage process moved the crack initiation location from the inner radius toward a mid-wall, and extended the crack initiation life. Predicted fatigue life of the fully autofrettaged pressure vessel with cross-bores increased about 50%, compared to the unautofrettaged pressure vessel. At the autofrettage level higher than 50%, the failure location and fatigue life of the pressure vessel were not significantly influenced by the autofrettage level.

• 한국공간구조학회논문집
• /
• 제6권3호
• /
• pp.77-86
• /
• 2006

본 논문은 횡하중을 받는 냉간성형 ㄷ 형강보의 응력해석에 관해 다루고 있다. 냉간형강 보에 가해지는 각 하중 레벨에서의 응력을 계산하여 국부좌굴과 횡좌굴을 고려하여 구조해석을 실시하였다. 해석모델은 박벽보의 기본이론에 의해 유도되었으며 1차원 보요소 유한요소해석을 통하여 수치해석을 하였다. 수치해석결과는 AISI 규준과 비교되었으며, 본 연구에서 제안된 해석모델이 냉간형강보의 처짐뿐 아니라 응력도 매우 정확히 예측함을 알 수 있었다.

• 한국방재학회:학술대회논문집
• /
• 한국방재학회 2008년도 정기총회 및 학술발표대회
• /
• pp.67-70
• /
• 2008

This study is to analyzes the global behavior of frame structures with local cracks in structural members by frame analysis, using the stiffness matrix of cracked frame element. This local compliance is utilized to derive the stiffness matrix of the cracked frame element and the effects of interaction among multiple cracks are also examined. The proposed technique is applied to frame structures with local cracks. Analysis results confirm the possibility of quantitative analysis of a structure damaged with local cracks and the feasibility of the technique as a tool for analyzing the global behavior of frame structures, reflecting effects of local cracks.

• 대한기계학회논문집A
• /
• 제30권9호
• /
• pp.1086-1093
• /
• 2006

A local failure criterion for the API X65 steel is applied to predict ductile failure of full-scale API X65 pipes with simulated corrosion and gouge defects under internal pressure. The local failure criterion is the stress-modified fracture strain for the API X65 steel as a function of the stress triaxiality (defined by the ratio of the hydrostatic stress to the effective stress). Based on detailed FE analyses with the proposed local failure criteria, burst pressures of defective pipes are estimated and compared with experimental data. The predicted burst pressures are in good agreement with experimental data. Noting that an assessment equation against the gouge defect is not yet available, parametric study is performed, from which a simple equation is proposed to predict burst pressure fur API X65 pipes with gouge defects.

• Steel and Composite Structures
• /
• 제18권1호
• /
• pp.273-288
• /
• 2015

As one of the most common failure types of arch bridges, stability is one of the critical aspects for the design of arch bridges. Using 3D finite element model in ABAQUS, this paper has studied the stability performance of an arch bridge with inclined arch ribs and hangers, and the analysis also took the effects of geometrical and material nonlinearity into account. The impact of local buckling and residual stress of steel plates on global stability and the applicability of fiber model in stability analysis for steel arch bridges were also investigated. The results demonstrate an excellent stability of the arch bridge because of the transverse constraint provided by transversely-inclined hangers. The distortion of cross section, local buckling and residual stress of ribs has an insignificant effect on the stability of the structure, and the accurate ultimate strength may be obtained from a fiber model analysis. This study also shows that the yielding of the arch ribs has a significant impact on the ultimate capacity of the structure, and the bearing capacity may also be approximately estimated by the initial yield strength of the arch rib.

• 한국자동차공학회논문집
• /
• 제4권2호
• /
• pp.80-89
• /
• 1996

Fatigue life of a notched shaft was evaluated in order to estimate the durability and integrity of the notched shaft in design stage. Cumulative fatigue dama- ge analysis was performed using local strain approach based on the assumption that the fatigue life of a notched component is approximately same as that of a smooth specimen is subjected to the same strain at the notched component. In this paper, shafts with different notch root radius of 1, 2㎜ resulting in different values of stress concentration factors were tested under||rotating bending fatigue loading condition. Theoretical stress concentration factor for each notch type was calculated using finite element method. Fatigue life prediction program, FALIPS, written in C language was developed using the strain-life curve, and the local strain approach integrating Neuber's rule, cyclic stress-strain, and hysteresis loop equations. The fatigue life evaluated using the fatigue notch factor obtained from the experimentally determined fatigue strength showed very large scattering with nonconservatism, but the fatigue notch factors derived from the stress concentration factors and Peterson's equation reduced the considerablely accurate fatigue life evaluation within a factor of three.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2007년도 정기 학술대회 논문집
• /
• pp.405-410
• /
• 2007

We present a new global/local analysis with the aid of MLS(Moving Least Square)-based finite elements which can handle an arbitrary number of nodes on every element side. It give a great flexibility in constructing finite element meshes at the specified local regions without remeshing. Compared to other type global/local analysis, it does not require any superimposed mesh or need not solve the equilibrium equation twice as well as shows an excellent accuracy. To demonstrate the performance of proposed scheme, we will show several examples in relation to capturing highly local stress field.

• 터널과지하공간
• /
• 제27권1호
• /
• pp.39-49
• /
• 2017

다양한 암반구조물의 안전도를 정량적으로 표현하는 지수로 안전율이 흔히 사용된다. 그러므로 동일한 응력조건에서 산정된 안전율이라 할지라도 안전율의 정의에 따라 안전율 계산 값의 차이가 있을 수 있으므로 적용하는 안전율의 정의와 특성을 이해하는 것이 중요하다. 이 연구에서는 Mohr-Coulomb 파괴조건식과 Hoek-Brown 파괴조건식을 활용하여 최대전단응력, 최대전단강도, 응력불변량, 최대주응력을 기반으로 하는 4종의 국부안전율을 정의하였다. 이어서 5가지 응력경로에 따른 각 안전율의 변화특성을 고찰하였다. 암반구조물 해석시 전통적으로 많이 이용되고 있는 전단강도 기반의 국부안전율은 최대주응력 및 응력불변량 기반의 안전율에 비해 높은 안전율 값을 계산함을 보였다. 이러한 결과는 보수적 암반공학적 설계가 필요한 경우 전단강도 기반의 국부안전율보다 최대전단응력이나 응력불변량 기반의 국부안전율 도입이 필요하다는 것을 말해준다. 또한 응력경로에 따라 파괴 시 최대주응력 값도 큰 차이가 있을 수 있음을 보였다.