• Journal of the Korean Society for Precision Engineering
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• v.20 no.5
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• pp.132-139
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• 2003

In this study, it is attempted to obtain the optimum size of holes in 15 square plate models where a hole exists on every quadrant of a plate, and to get eigenvalues by performing free vibration analysis for each model. Moreover, the specimen is produced from optimized square plate and eigenvalue of each plate is measured through the shocking load. And then the result is compared with that of finite element analysis. For free vibration analysis of the square plate, the boundary condition of finite element analysis and experiment is assumed as both ends clamped support. From the results of this study, it is known that more stable structures can be designed by changing the natural frequency which is dependent on the location of holes and further studies are considered to be necessary fur the basic design information.

• Journal of Ocean Engineering and Technology
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• v.26 no.4
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• pp.70-76
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• 2012

The independent component analysis (ICA) technique is a source identification method that uses statistical independence to separate source signals from measured signals. It has been successfully applied to various fields such as medical care and communication. In this study, the ICA technique was adopted to analyze the vibration source contribution of plate structures. The theory of the ICA technique is introduced and the procedure of the vibration source contribution analysis based on the ICA technique is proposed. To investigate the applicability of the proposed method to plate structures, numerical examples are presented for a rectangular plate under harmonic force excitations. The results show that the proposed method could become an effective tool for the vibration source contribution analysis of a plate structure.

• Steel and Composite Structures
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• v.29 no.6
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• pp.771-783
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• 2018

In this paper, topology optimization (TO) is applied to find a new configuration for the perforated steel plate shear wall (PSPSW) based on the maximization of reaction forces as the objective function. An infill steel plate is introduced based on an experimental model for TO. The TO is conducted using the sensitivity analysis, the method of moving asymptotes and SIMP method. TO is done using a nonlinear analysis (geometry and material) considering the buckling. The final area of the optimized plate is equal to 50% of the infill plate. Three plate thicknesses and three length-to-height ratios are defined and their effects are investigated in the TO. It indicates the plate thickness has no significant impact on the optimization results. The nonlinear behavior of optimized plates under cyclic loading is studied and the strength, energy and fracture tendency of them are investigated. Also, four steel plates including infill plate, a plate with a central circle and two types of the multi-circle plate are introduced with equal plate volume for comparing with the results of the optimized plate.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.551-556
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• 2004

The theoretical method is developed to investigate the vibration characteristics of the combined cylindrical shells with an annular plate joined to the shell at any arbitrary axial position. The structural rotational coupling between shell and plate is simulated using the rotational artificial spring. For the translational coupling, the continuity conditions for the displacements of shell and plate are used. For the uncoupled annular plate, the transverse motion is considered and the in-plane motions are not. And the additional transverse and in-plane motions of the coupled annular plate by shell deformation are considered in analysis. Theoretical formulations are based on Love's thin shell theory. The frequency equation of the combined shell with an annular plate is derived using the Rayleigh-Ritz approach. The effect of inner-to-outer radius ratio, axial position and thickness of annular plate on vibration characteristics of combined cylindrical shells is studied. To demonstrate the validity of present theoretical method, the finite element analysis is performed.

• Journal of the korean Society of Automotive Engineers
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• v.11 no.1
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• pp.44-50
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• 1989

Using modal analysis method this paper examines the dynamic characteristics of composite material closely. Composite material is superior to conventional material in view of mechanical properties. So the laminate of CFRPis compared with ALPlate. As the results, the overall vibration level of CFRP is lower than that of AL Plate and is low when fiber direction is parallel to the fixed point. Also, the natural frequency of CFRP is situated in low frequency than that of AL.

• Journal of Ocean Engineering and Technology
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• v.19 no.1 s.62
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• pp.33-38
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• 2005

It has been well documented that plate forming is one of the most important processes in shipbuilding. In the most shipyards, the line heating method is primarily used for plate forming. Since the heating process is carried out for the curved plate and not for the flat plate, a curvature effect on the final deformation must be considered in deriving the simplified prediction models for deformation. This paper investigates the effect of curvature along the heating line on the deformation of the plate. First of all, results of numerical analysis are compared with these of a line-heating test, to justify the elasto-plastic analysis procedure for the present study, which shows good agreement. Then, the present numerical procedure is applied to flat and curved plate models, to investigate the curvature effect on the heat transfer characteristics and deformation by line heating.

• Wind and Structures
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• v.25 no.1
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• pp.25-38
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• 2017

This study investigates the dynamic analysis of a transversely isotropic thin plate. The plate is made of hyperelastic John's material and its constitutive law is obtained by taken the Frechect derivative of the highlighted energy function with respect to the geometry of deformation. The three-dimensional equation governing the motion of the plate is expressed in terms of first Piola-Kirchhoff's stress tensor. In the reduction to an equivalent two-dimensional plate equation, the obtained model generalizes the classical plate equation of motion. It is obtained that the plate under consideration exhibits harmonic force within its planes whereas this force varnishes in the classical plate model. The presence of harmonic forces within the planes of the considered plate increases the natural and resonance frequencies of the plate in free and forced vibrations respectively. Further, the parameter characterizing the transversely isotropic structure of the plate is observed to increase the plate flexural rigidity which in turn increases both the natural and resonance frequencies. Finally, this study reinforces the view that non-classical models of problems in elasticity provide ample opportunity to reveal important phenomena which classical models often fail to apprehend.

• International Journal of Aeronautical and Space Sciences
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• v.18 no.3
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• pp.450-466
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• 2017

This paper defines the modified effective membrane stiffness, bending stiffness considering the directionally dependent mechanical properties and mode shape function of a composite lattice rectangular plate, which is assumed to be a Kirchhoff-Love plate. It subsequently presents an approximate method of conducting a buckling analysis of the composite lattice rectangular plate with various boundary conditions under uniform compression using the Ritz method. This method considers the coupled buckling mode as well as the global and local buckling modes. The validity of the present method is verified by comparing the results of the finite element analysis. In addition, this paper performs a parametric analysis to investigate the effects of the design parameters on the critical load and buckling mode shape of the composite lattice rectangular plate based on the present method. The results allow a database to be obtained on the buckling characteristics of composite lattice rectangular plates. Consequently, it is concluded that the present method which facilitates the calculation of the critical load and buckling mode shape according to the design parameters as well as the parametric analysis are very useful not only because of their structural design but also because of the buckling analysis of composite lattice structures.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11a
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• pp.341-348
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• 2001

In this study, nonlinear vibration analysis of the cylindrical orthotropic porous thin plate under V-shaped tension distribution with wire impact damping is considered. We make dynamic model of the plate under the tension using commercial FEM code and reduce the number of its degrees of freedom using dynamic condensation. The dynamic model of wire is obtained as lumped mass model from string equation. And then we analyze the nonlinear vibration of the plate including the impact phenomenon between the plate and the wire using the reduced mass and stiffness matrices of the plate and lumped model of the wire. The contact phenomenon between them can be described by impact contact elements composed of contact stiffness coefficients from Hertzian contact theory and contact damping coefficients from restitution coefficient between them. And we discussed the results of nonlinear vibration analysis for variations of their design parameters.

• Journal of the Society of Naval Architects of Korea
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• v.40 no.6
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• pp.37-48
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• 2003

A study for the structural strength evaluation of doubler plates subjected to the in-plane combined load and lateral pressure load has been performed through a systematic evaluation process. In order to properly estimate the static strength of doubler plate, elasto-plastic large deflection analysis is introduced including the contact effect between main plate and doubler. The characteristics of stiffness and strength variation are discussed based on the analysis results. Also, in order to compare the doubler structure with the original strength of main plate without doubler, a simple formula for the evaluation of the equivalent flat plate thickness is derived based on the additional series analysis of fiat plate structure. Using this derived equation, the thickness change of a equivalent flat plate is analyzed according to the variation of various design parameters of doubler plate and some design guides are suggested In order to maintain the original strength of main plate without doubler reinforcement. Finally, correlation between derived equivalent plate thickness formula and the developed buckling strength formulas for intact plates by author et al. is discovered and these relations are formulated for the future development of simple strength evaluation formula of doubler plate structure.