• Proceedings of the KWS Conference
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• 1992.10a
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• pp.230-232
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• 1992

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2009.04a
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• pp.446-449
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• 2009

본 연구에서는 강관말뚝과 기초와의 연결시 보강에 사용되는 관통형 말뚝두부보강에 대한 파괴거동을 파악하기 위한 구조해석을 수행하였다. 구조물의 관공부에 대한 해석에서 철근의 인장파괴시 발생하는 관통부의 응력을 검토하고 철근의 파괴형상과 실험에서 얻어진 철근의 파괴형상을 비교하였다. 대상구조물의 전체적인 파괴거동은 인장, 압축, 전단, 휨모멘트에 대하여 파괴가 발생할 때까지 변위를 증가시키고 이때 발생하는 반력과 구조물의 파괴거동을 파악하였다. 이 때 강재의 비선형 거동 및 충진콘크리트의 비선형및 균열거동이 고려되었다. 해석의 결과로 대상구조물의 파괴거동 및 극한하중 저항능력이 평가되었다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.1
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• pp.106-114
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• 2001

In this study, a shape optimization of stiffener was conducted to increase buckling load or failure load in each case with a different design value and a different objective function for stiffened laminated composite panel of I-type under compression loading. Regarding each of buckling load or failure load as objective function, optimum design was carried out. In respect of optimum design, the effects of relative length of web and cab of stiffener on buckling load or failure load of postbuckling were investigated.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.5
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• pp.833-839
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• 2003

The effects of stiffeners on the modal characteristics of rectangular plates are investigated. A modeling method for the modal analysis of rectangular plates with stiffeners is presented. A mass density Dirac's delta function is used to idealize the stiffeners mathematically. The equations of motion for the plates are derived and transformed into a dimensionless form. To confirm the accuracy of the method presented in this study, numerical result are obtained and compared to those of a commercial program. The mode shape variations due to some parameter variations are also exhibited.

• Journal of KSNVE
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• v.10 no.2
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• pp.312-318
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• 2000

A modeling method for the vibration analysis of rotating cantilever plastes with stiffeners is presented. The equations of motion for the plates aer derived and trnasformed into a dimensionless form. A mass density Dirac's delta function is used to idealize the stiffener mathematically. The effects of stiffeners on the model characteristics of the plate are investigated, and mode shape variations due to some parameter variation are exhibited. It is found that veering phenomena occur between some loci and associated mode shapes change significantly during the veering phenomena.

• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.3
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• pp.350-357
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• 2012

The velocity response of stiffened rectangular plate under high velocity impact was studied. Numerical simulation was conducted on the stiffened plate with four stiffeners under various impact positions. Considered stiffener types were rib, I, hat and T stiffener. For the center impact position of I stiffened plate, the simulated residual velocity was 365.6 m/s with the initial projectile velocity 500 m/s. The reinforcing characteristic of I stiffened plate was excellent among four stiffeners.

• Journal of Mechanical Science and Technology
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• v.16 no.10
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• pp.1211-1221
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• 2002

A shape optimization of stiffener was conducted to increase buckling load or failure load with stiffened laminated composite panel of I-type under compression loading. Design variables are cap length, web length, and/or thickness under the constraint of volume constancy. The objective function is buckling load and failure load of post-buckling based on Tsai-Hill theory using ABAQUS 5.8 for analysis and Optimizer on Broydon-Fletcher Goldfarb-Sharno Method and Augmented Lagrange Multiplier Method. The effects of relative length of a web and a cap of stiffener on buckling load and failure load of post-buckling were investigated with the results of optimum design.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.7
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• pp.2223-2233
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• 1996

The analytical solutions for the free vibration of cross-ply laminated composite cyllindrical shell with axial stiffeners(stringers) are presented usint the energy method. The stiffeners are taken to be smeared over the surface of shell with the smeared stffener theory. The effect of the parameters such as the stacking sequences, the shell thichness, the shell radius-to stringer depth ratio, the stringer depth-to width ratio, the shell length-to radius ratio are studied. By comparison with the previously published experimental results and the analytical results for the stiffened isotropic cylindrical shell and the unstiffened orthotropic composite laminated cylindrical shell, it is shown that natural frequencies can be determined with adequate accuracy.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.599-604
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• 2002

Substructures position is considered as design parameter to obtain optimal structural changes to raise its dynamic characteristics. In conventional SDM (structural dynamics modification) method, the layout of modifying substructures position is first fixed and at that condition the structural optimization is performed by using the substructures size and/or material property as design parameters. But in this paper as a design variable substructures global translational and rotational position is treated. For effective structural modification the eigenvalue sensitivity with respect to that design parameter is derived based on measured frequency response function. The optimal structural modification is calculated by combining eigenvalue sensitivities and eigenvalue reanalysis technique iteratively. Numerical examples are presented to the case of beam stiffener optimization to raise the natural frequency of plate.

• Bulletin of the Society of Naval Architects of Korea
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• v.24 no.3
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• pp.35-42
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• 1987

For the analysis of natural vibrations of a rectangular stiffened plate with inner cutouts, an application of the Rayleigh-Ritz method is investigated. In construction of the trial function for the Rayleigh quotient, only the outer boundary conditions are satisfied with combination of Euler beam functions. As to the modeling of stiffened plates for the energy calculations, a lumping stiffener-effects method and the orthotropic plate analogy are considered for the purpose of comparison. Some numerical results obtained by the Rayleigh-Ritz method are compared with results by experiments and the finite element method. The following are major conclusions; (1) With the lumping stiffener-effects modeling the Rayleigh-Ritz method gives good results of both natural frequencies and mode shapes. The orthotropic plate analogy in cases of regularly stiffened plates is of restrictive use i.e. acceptable for a small cutout. (2) The natural frequency of a stiffened plate with inner cutouts between stiffeners is higher than that of without cutouts and increase as the hole area ratio increases as long as there are no discontinuous stiffeners due to the cutout.