• 대한조선학회지
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• 제10권1호
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• pp.15-20
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• 1973

In this paper, it is desired to show a simplified analytical method in estimating the thermal stresses in the heat affected zone of butt welded joint. A finite strip as shown in Fig.1 is taken as a analytical model for stress analysis. Expressing the temperature distributions by Fourier series, the thermal stresses are obtained. From the numerical sample calculation, the following results can be obtained. (1) Thermal stresses can be estimated by the sujected method. (2) The stress component, which is parallel to the weld direction is the largest stress component in major part of the strip. (3) In obtaining a stress component for the engineering purpose, length of the strip can be treated as five times of the thickness with same degree of convergency.

• 대한기계학회논문집
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• 제16권8호
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• pp.1451-1457
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• 1992

본 연구에서는 작업롤의 온도분포를 정상 상태에서 롤의 길이 방향만을 고려 한 경우에 대하여 구한 다음 Fouries 급수로 전개하여 이 온도분포에 따른 작업롤의 축대칭 3차원 열-탄성문제를 해석함으로서 롤의 크라운 양과 열응력을 구하여 이 결과 를 유한요소법에 의한 결과와 비교 검토 하였다.

• Journal of Welding and Joining
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• 제22권3호
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• pp.62-68
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• 2004

The strip Au bumps are bonded using longitudinal ultrasonic far the electronic package. Au bumps on the chip and substrate are aligned in a crossed shape, and the ultrasonic is imposed on the chip to form the solid-state bond between the Au bumps. Deformed bump shapes are calculated using the finite element method, and the bond strength is measured experimentally. The crossed strip Au bumps are deformed similar to the saddle, which provides larger contact surface area and higher friction force. Compared with the previous bonding method between the Au bump and planar pad, higher bond strength is obtained using the crossed strip bumps.

• 한국항행학회논문지
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• 제15권4호
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• pp.543-548
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• 2011

본 논문에서는 스트립 폭과 격자주기, 유전체 층의 비유전율과 두께, 그리고 TE(transverse electric) 평면파의 입사각에 따른 접지된 유전체 평면위의 변하는 저항율을 갖는 저항띠 격자구조에 의한 H-분극 전자파 산란문제를 FGMM(Fourier-Galerkin Moment Method)를 이용하여 해석하였다. 저항띠의 변하는 저항율은 한쪽 모서리에서는 유한하고 다른쪽 모서리에서 0 저항율을 가지며, 이때 저항띠 위에서 유도되는 표면 전류밀도는 직교다항식의 일종인 차수가 ${\alpha}=1$, ${\beta}=0$인 Jacobi 다항식의 급수로 전개하였다. 정규화된 반사전력의 수치결과는 기존의 수치결과와 매우 일치하였다.

• Computers and Concrete
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• 제8권6호
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• pp.717-733
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• 2011

Strengthening of reinforced concrete (RC) members against shear that is one of the failure modes especially avoided by using carbon fiber reinforced polymer (CFRP) is widely used technique, which is studied at many experimental studies. However, conducting experimental studies are required more financial resources and laboratory facilities. In addition, along with financial resources, more time is needed in order to carry out comprehensive experimental studies. For these reasons, a verified finite element model that is tested with previous experimental studies can be used for reaching generalized results and investigating parameters that are not studied. For this purpose, previous experimental study results are used and "T" cross-sectioned RC beams strengthened with CFRP strips with insufficient shear strength are modeled by using ANSYS software. First, finite elements modeling of the previously tested RC beams are done, and then the computed results are compared with the experimental ones whether they are matched or not. As a result, the finite element model is verified. Later, analyses of the cases without any test results are done by using the verified model. Optimum CFRP strip spacing is determined with this verified finite element model, and compared with the experimental findings.

• 소성∙가공
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• 제13권6호
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• pp.497-502
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• 2004

The shape of cold rolled steel sheets is defined as the degree of flatness, and the flatter, the better. Because undesirable strip shapes of cold rolled steel sheets can affect not only visible problem but also automatic working process in customer's lines, the requirement of the customers is more and more stringent. So we usually used the tension leveler to make high quality of strip flatness. For the improvement of the quality of strip flatness, this report developed three- dimensional FEM (Finite Element Method) simulation model, and analysis about the strain and stress distribution of strip in the tension leveling process. The numerical study can be summarized as follows. (1) If we pass the edge wave material (steepness: $1.0\%$) that the stress-difference between the strip center and the edge is 5.2kgf through tension leveler. the stress-difference is decreased 0.45kgf and the steepness is improved to $0.29\%$. (2) If the Intermesh is increased from 6mm to 7mm, the steepness is improved from $0.294\%$ to $0.268\%$. (3) If the initial steepness is decreased form $1.0\%$ to $0.75\%$, the final steepness is improved from $0.294\%$ to $0.263\%$. We know that more increased intermesh and lower initial steepness make the final steepness improved.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1999년도 춘계학술대회논문집
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• pp.207-212
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• 1999

A computational method based on the three-dimensional finite element method is developed for the deformation analysis of roll forming process. the method approximates the process as a kinematically steady state deformation of strip. For industrial usefulness of the simulation method several rolls with arbitrary shapes in one stand can be considered. The shapes and the thickness distributions of strip after roll forming were examined by comparing computation results with experiments It is concluded that the tool is useful enough to predict the process. The overall simulation method was integrated into a sorftware package to help the industrial roll-design.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1995년도 춘계학술대회논문집
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• pp.233-237
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• 1995

Effects of frictional laws on finite element solutions in bulk metal forming were investigated in this paper. The Coulomb friction and the constant shear friction law were compared through finite element anlayses of compression of ring and cylinders with different aspect rations, ring-gear forging and hot strip rollin under the isothermal condition. It has been shown that two laws may yield quite different results inthe case that the aspect ration of a process is large, for example , strip rolling and ring -gear forging and that the difference depends mainly on the aspect ratio and the friction.

• Progress in Superconductivity
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• 제13권3호
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• pp.151-157
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• 2012

In this paper, we used E-J constitutive law and H-formulation to calculate magnetic field profile, current density, and magnetization of high temperature superconductor (HTS) placed in time varying applied magnetic field. Finite element method (FEM)-based software, Comsol Multiphysics 3.5a, was employed to simulate 2-dimensional model of a superconducting thin strip. The numerical results based on Kim's critical state model were compared with the case of strip in a perpendicular field in the Brandt's paper as well as experimental data observed by Scanning Hall Probe and SQUID.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2001년도 추계학술대회 논문집
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• pp.121-124
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• 2001

On-line prediction model which calculate roll force, roll power and forward slip of continuous hot strip rolling was built based on the results of plane strait rigid-viscoplastic finite element process model. Using the integrated FE process model, a series of finite element simulation was conducted over the process variables, and the influence of various process conditions on non-dimensional parameters was inspected. The prediction accuracy of the proposed on-line model under front and back tension is examined through comparison with predictions from a finite element process model over the various process conditions. In addition, we examined the validity of the on-line prediction model through comparison with roll force of experiment in hot rolling.