• Structural Engineering and Mechanics
• /
• 제22권6호
• /
• pp.741-759
• /
• 2006

A general theory which describes the elastic response of a curved anisotropic plate subjected to stretching and bending will be developed by considering the nonlinear effect that reflecting the non-flat geometry of the structure. By applying a newly derived $6{\times}6$ matrix constitutive relation between force resultants, moment resultants, mid-plane strains and deformed curvatures, the governing differential equations for a curved anisotropic plate is developed in the usual manner, namely, by consideration of the constitutive relation and equilibrium equations. Solutions are obtained for simply-supported boundary conditions and compared to corresponding solutions that neglecting the nonlinear effect in the analysis. The comparisons indicate that the nonlinear terms in the equations that caused by the curvature of the structure is crucial for the curved plate analysis. Under certain curved plate geometries the unreasonable results will be induced by neglecting the nonlinear effect in the analysis.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1996년도 봄 학술발표회 논문집
• /
• pp.317-322
• /
• 1996

The objective of this study is to investigate the characteristics of elastic and inelasitc behavior of ductile moment-resisting reinforced concrete frame subhected to reversed lateral loading such as eqrthquake excitations. For this purpose, a 2-bay 2-story R.C. plane frame with seismic detail was designed and one 1/2.5-scale subassemblage was manufactured according to the required similitude law. Then the reversed load test under the displacement control was performed statically to this subassemblage. Finally the results of this test were analysed regarding to (1) the design load vs actual strength, (2) degradation in stiffness and strength, (3) failure mode or main plastic mechanism in energy dissipation, (4) local deformations.

• 전자공학회논문지S
• /
• 제34S권9호
• /
• pp.99-108
• /
• 1997

An efficient wavelet packet algorithm to find wavelet packet quickly is presented in this paper. The top-down method maximizing the transform coding gain that is obtained from the second moment of the band is used to divide the subbands into wavelet tree. The bit allocation for each band in the tree is performed in proportion to its variance. Bands are coded by the lossless coding algorithm called the bit plane run length coding(BPRLC) and uniform quantizer. The proposed algorithm is compared with of the single tree algorithim proposed by Ramchandran and Vetterli. To verify the efficiency of our algorithm, simulations are jperformed using several sets of images. The results show us that our method reduces the execution time by about forty percent of that required by the single tree method while maintaining the comparable reconstructed image qualities.

• 대한기계학회논문집A
• /
• 제32권1호
• /
• pp.91-98
• /
• 2008

One of the two spindles in the X-lift fractured suddenly during normal operation. The fracture occurred at the notch where the bending moment might be the maximum. Macrofractographic features associated with rotating-bending fatigue are evident on the fracture surface. The 3-D finite element analysis of the X-lift reveals that the spindle rotated under bending. The measured surface strain of the spindle varies cyclically as the spindle rotates. It supports that the spindle rotated under bending. The X-lift is not perfectly symmetrical with respect to both the horizontal and the vertical plane. The slightly unsymmetrical deformation can cause the bending of the spindle.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2008년도 추계학술대회A
• /
• pp.402-407
• /
• 2008

We suggest a linear elastic flat shell element based on the HT(hybrid Trefftz) method. We formulate the membrane part of the proposed element as an HT plane element with the drilling DOF. For the bending part, we developed a thick HT plate element that can represent transverse shear deformations accurately. Because we derive both the membrane and the bending parts consistently using the HT functional, we can easily construct the triangular and the quadrilateral elements in a unified way. In addition, warping of quadrilateral element is compensated by force and moment equilibrium equations. We evaluate the performance of the new element in terms of accuracy and convergence.

• 한국통신학회논문지
• /
• 제13권5호
• /
• pp.444-452
• /
• 1988

高利得과 廣帶域 特性을 동시에 실현하기 위하여 원형 루프 안테나를 傳送線路에 의하여 交叉給電시킨 素子와 無給電 素子로 구성한 LP형태의 안테나를 제시했다. 제시한 안테나를 모멘트法에 의하여 數値解析하여 電流分布, 入力임피던스, 電力利得 및 指向性 패턴 등을 對數週期 다이폴 안테나(LPDA)와 比較 檢討하였다. 그 결과 本 論文에서 제시된 안테나는 廣帶域 特性 밑 高利得을 갖고 周波數에 따른 E, H面패턴의 변화가 거의 없었으며 LPDA보다 우수한 性能을 갖는 것으로 확인 되었다.

• Journal of Welding and Joining
• /
• 제28권5호
• /
• pp.64-68
• /
• 2010

The purpose of this study is to develop the control technology of global distortion in the deck of superstructures during manufacturing processes. The behavior of global distortion in the deck was evaluated by FEA and verified through comparing with the measured results by 3D measuring instrument. It was seen from the results that the principal factor inducing the global distortion is to be the bending moment associated with the longitudinal shrinkage force and transverse shrinkage caused by welding of stiffeners and flame heating to correct the excessive local out-of-plane distortion. Based on the results, the amount of reverse distortion in the thin deck plate was determined to control the global distortion in the deck plate. The proposed distortion control technology was verified by applying it to the actual structure.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
• /
• pp.439-441
• /
• 1988

The induced currents on a uniform resistive strip by a H-polarized plane wave are obtained by the iteration method in the spectral domain and compared with the results by the moment method.

• 대한전자공학회논문지
• /
• 제25권2호
• /
• pp.125-129
• /
• 1988

The acattering characteristics by the TE incident wave are analysed for its dielectric cylinder with arbitrary cross section partially covered by thin conductors. The integro differential equations consistent with boundary conditions of conductors and dielectric boundaries are derived by the equivalence principle. They are transformed into matrix equations by moment method. The rectangular dielectric ctlinder partially coverd by conductors at the upper and bottom side of the cylinder is chosen for the numerical example. Current distributions on conductors and sacttring cross sections by the cylinder are computed for the TE incident perpendicular to the conductor plane.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1996년도 가을 학술발표회 논문집
• /
• pp.401-407
• /
• 1996

A 2-bay 2-story moment-resisting reinforced concrete plane frame with seismic detail was designed. One 1/2.5-scale and one 1/10th model subassemblages were manufactured accoring to the required similitude law. Then the reversed load tests under the displacement control were performed statically to these subassemblages. The results of these tests were compared regarding to the similitude in the characteristics of structural behaviors such as strength., stiffness, energy dissipation, failure modes and local deformations. Based on these results, the following conclussions were drawn : (1) The strength of 1/10 model was very similar to that of 1/2.5 specimen. (2) The initial stiffness of 1/10 model appers to be approximately 2/3 of that of 1/2.5 specimen. (3) 1/10 model has therefore smaller energy dissipation capacity than 1/2.5 specimen. (4) Inelastic excursion mechanisms of 1/2.5 specimen and 1/10 model apper to be a little different.