• 대한기계학회논문집
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• 제17권7호
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• pp.1794-1804
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• 1993

The thermal stress intensity factors for interface cracks of Griffith and symmetric lip cusp types under vertical uniform heat flow in a finite body are calculated by boundary element method. The boundary conditions on the crack surfaces are insulated or fixed to constant temperature. The relationship between the stress intensity factors and the displacements on the nodal point of a crack tip element is derived. The numerical values of the thermal stress intensity factors for interface Griffith crack in an infinite body and for symmetric lip cusp crack in a finite and homogeneous body are compared with the previous solutions. The thermal stress intensity factors for symmetric lip cusp interface crack in a finite body are calculated with respect to various effective crack lengths, configuration parameters, material property ratios and the thermal boundary conditions on the crack surfaces. Under the same outer boundary conditions, there are no appreciable differences in the distribution of thermal stress intensity factors with respect to each material properties. But the effect of crack surface thermal boundary conditions on the thermal stress intensity factors is considerable.

• Structural Engineering and Mechanics
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• 제6권1호
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• pp.115-124
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• 1998

A novel boundary stress resolution method is suggested in this paper, which is based upon the displacements of finite element analysis and of high precision with stress boundary condition strictly satisfied. The method is used to modify the Zienkiewicz-Zhu ($Z^2$) a posteriori error estimator and for the h-version adaptive finite element analysis of crack problems. Successful results are obtained.

• Nuclear Engineering and Technology
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• 제50권7호
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• pp.1131-1137
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• 2018

The effect of a serrated grain boundary on stress corrosion cracking (SCC) of Alloy 600 was investigated in terms of improvement of SCC resistance. Serrated grain boundaries and straight grain boundaries were obtained by controlled heat treatment. SCC cracks preferentially initiated and grew at grain boundaries normal to the tensile loading axis. Resolved tensile stress normal to the grain boundary was lower in serrated grain boundaries compared to straight grain boundaries. The specimen with serrated grain boundaries showed higher SCC resistance than that with straight grain boundaries due to a lower resolved tensile stress normal to the grain boundary.

• 한국자동차공학회논문집
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• 제16권3호
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• pp.15-22
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• 2008

Applications of bonded dissimilar materials such as integrated circuit(IC) packages, ceramics/metal and resin/metal bonded joints, are very increasing in various industry fields. It is very important to analyze the thermal stress and stress singularity at interface edge in bonded joints of dissimilar materials. In order to investigate the IC package crack propagating from the edge of die pad and resin, the fracture parameters of bonded dissimilar materials and material properties are obtained. In this paper, the thermal stress and its singularity index for the IC package were analyzed using 2-dimensional elastic boundary element method(BEM). From these results, crack propagation direction and path by thermal stress in the IC package were numerically simulated with boundary element method.

• 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.

• 디지털융복합연구
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• 제11권11호
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• pp.603-611
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• 2013

본 연구는 병원종사자를 대상으로 직무스트레스, 조직몰입, 고객지향영역초월행동에 미치는 구조적 관계를 알아보고자 하였다. 서울 및 경기에 근무하는 병원종사자를 대상으로 2013년 4월1일부터 4월30일까지 배포하여 최종적으로 147부의 설문을 SPSS 18.0와 AMOS 18.0프로그램을 이용하여 실증 분석하는데 사용하였다. 분석결과, 가설 1의 병원종사자들의 직무스트레스가 조직몰입에 부(-)적인 영향을 미치는 것으로 나타났다. 가설 2의 병원종사자들의 조직몰입은 고객지향영역초월행동에 정(+)적인 영향을 미치는 것으로 나타났다. 가설 3의 병원종사자들의 직무스트레스가 고객지향영역초월행동에 부(-)적인 영향을 주는 것으로 나타났다. 따라서 병원종사자들의 조직몰입은 직무스트레스와 고객지향영역초월행동 간의 관계에서 부분적 매개역할을 하는 것을 알 수 있었다. 병원이 경쟁력을 가지기 위해서는 서비스품질을 향상시켜야 한다. 따라서 가장 중추적인 역할을 하는 병원종사자들의 스트레스를 줄이는 방안을 마련함으로써 조직몰입을 증가시킬 수 있으며 고객과의 접점에 있는 종사자들의 고객지향초월영역행동을 높일 수 있을 것이라는 점을 시사한다.

• East Asian mathematical journal
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• 제33권1호
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• pp.1-9
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• 2017

In [8] they introduced a new finite element method for accurate numerical solutions of Poisson equations with corner singularities, which is useful for the problem with known stress intensity factor. They consider the Poisson equations with homogeneous Dirichlet boundary condition, compute the finite element solution using standard FEM and use the extraction formula to compute the stress intensity factor, then they pose a PDE with a regular solution by imposing the nonhomogeneous boundary condition using the computed stress intensity factor, which converges with optimal speed. From the solution they could get accurate solution just by adding the singular part. This approach works for the case when we have the reasonably accurate stress intensity factor. In this paper we consider Poisson equations defined on a domain with a concave corner with Neumann boundary conditions. First we compute the stress intensity factor using the extraction formular, then find the regular part of the solution and the solution.

• 설비공학논문집
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• 제15권11호
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• pp.895-901
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• 2003

Direct numerical simulation database of an axial turbulent boundary layer is used to compute frequency and wave number spectra of the wall shear-stress fluctuations in a low-Reynolds number axial turbulent boundary layer. One-dimensional and two-dimensional power spectra of flow variables are calculated and compared. At low wave numbers and frequencies, the power of streamwise shear stress is larger than that of spanwise shear stress, while the powers of both stresses are almost the same at high wave numbers and frequencies. The frequency/streamwise wave number spectra of the wall flow variables show that large-scale fluctuations to the ms value is largest for the streamwise shear stress, while that of small-scale fluctuations to the rms value is largest for pressure. In the two-point auto-correlations, negative correlation occurs in streamwise separations for pressure and spanwise shear stress, and in spanwise correlation for both shear stresses.

• 한국생산제조학회지
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• 제4권4호
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• pp.33-41
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• 1995

This study includes thermal plasticity analyses for a turbine rotor with the simple geometry and the boundary conditions. When centrifugal or thermal stress are applied at the high temperature material of engine blade, stress distributions I material ($\sigma$${\gamma}$${\gamma}$, $\sigma$$\theta$$\theta$, $\tau$${\gamma}$$\theta$, Mises stress) are analyzed by computer simulation(ABQUS) as followings; 1. The maximum stress at the radial direction() is applied at the upper middle part of spline hole. 2. The maximum stress at the tangential direction() is applied at the upper right boundary of spline hole. 3. The maximum shear stress () in () direction is applied at the upper middle part of spline hole. 4. The maximum Mises stress is applied at the upper right boundary of spline hole. This stress is due to the critical stress by which rotor can be fractured according to elapsed time.

• 한국공작기계학회논문집
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• 제16권6호
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• pp.94-102
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• 2007

Applications of bonded dissimilar materials such as large scale integration (LSI) packages, ceramics/metal and resin/metal bonded joints, are very increasing in various industry fields. It is very important to analyze the thermal stress and stress singularity at interface edge in LSI. In order to investigate stress singularities on the bonded interface edges and delamination of die pad and resin in the IC package. In this paper, stress singularity factors(${\Gamma}_i$) and stress intensity factors($K_i$) considering thermal stress in the IC package were analyzed by using the 2-dimensional elastic boundary element method(BEM).