• Structural Engineering and Mechanics
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• v.34 no.2
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• pp.143-157
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• 2010

This paper presents theoretical solutions for the three-dimensional (3D) stress field in an infinite isotropic elastic plate containing a through-the-thickness circular hole subjected to far-field in-plane loads by using Kane and Mindlin's assumption. The dangerous position, where the premature fracture or failure of the plate will take place, the expressions of the tangential stress at the surface of the hole and the out-of-plane stress constraint factor are found in a concise, explicit form. Based on the present theoretical solutions, a comprehensive analysis is performed on the deviated degree of the in-plane stresses from the related plane stress solutions, stress concentration and out-of-plane constraint, and the emphasis has been placed on the effects of the plate thickness, Poisson's ratio and the far-field in-plane loads on the stress field. The analytical solution shows that the effects of the plate thickness and Poisson's ratio on the deviation of the 3D in-plane stress components is obvious and could not be ignored, although their effects on distributions of the in-plane stress components are slight, and that the effect of the far-field in-plane loads is just on the contrary of that of the above two. When only the shear stress is loaded at far field, the stress concentration factor reach its peak value about 8.9% higher than that of the plane stress solutions, and the out-of-plane stress constraint factor can reach 1 at the surface of the hole and is the biggest among all cases considered.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.311-318
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• 2001

A three-dimensional numerical analysis of the flow and heat transfer characteristic of wood-flour-filled polypropylene melt in an extrusion die was carried out Used for this analysis were Finite Concept Method based on FVM, unstructured grid and non-Newtonian fluid viscosity model. Temperature and flow fields are closely coupled through temperature dependent viscosity and viscous dissipation. With large Peclet, Nahme, Brinkman numbers, viscous heating caused high temperature belt near die housing, Changing taper plate thickness and examining some predefined parameters at die exit investigated the effect of taper plate on velocity and temperature uniformities. In the presence of taper plate, uniformity at die exit could be improved and there existed an optimum thickness to maximize it.

• Steel and Composite Structures
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• v.28 no.4
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• pp.495-508
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• 2018

In this paper, the effect of matrix cracks on the buckling of a hybrid laminated plate is investigated. The plate is composed of carbon nanotube reinforced functionally graded (CNTR-FG) layers and conventional fiber reinforced composite (FRC) layers. Different distributions of single walled carbon nanotubes (SWCNTs) through the thickness of layers are considered. The cracks are modeled as aligned slit cracks across the ply thickness and transverse to the laminate plane, and the distribution of cracks is assumed statistically homogeneous corresponding to an average crack density. The first-order shear deformation theory (FSDT) is employed to incorporate the effects of rotary inertia and transverse shear deformation, and the meshless kp-Ritz method is used to obtain the buckling solutions. Detailed parametric studies are conducted to investigate the effects of matrix crack density, CNTs distributions, CNT volume fraction, plate aspect ratio and plate length-to-thickness ratio, boundary conditions and number of layers on buckling behaviors of hybrid laminated plates containing CNTR-FG layers.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.11 no.4
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• pp.440-447
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• 1999

The frosting characteristics on the vertical parallel plates with three cooling plates were experimentally investigated. The experimental parameters were the cooling plate temperature, the air humidity, the air temperature, the air Reynolds number, and the location. The frosting conditions were limited to air temperatures from 10 to $15^{\circ}C$ , air Reynolds numbers from 1600 to 2270, air humidity ratios from 0.00275 to 0.0037kgw/kga and cooling plate temperatures from -10 to $-20^{\circ}C$. Frost growth and density toward the front of the plate were more thick and dense than toward the rear. Frost growth increased with decreasing plate temperature and increasing humidity. In the conditions of the laminar flow, dew point below $0^{\circ}C$and non-cyclic frosting period, frost thickness increased with increasing air temperature. The reason of increasing frost thickness with increasing air temperature was sublimation-ablimation process. The average growth thickness along the locations showed little dependence on the Reynolds numbers.

• Steel and Composite Structures
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• v.47 no.2
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• pp.297-313
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• 2023

This study aims to extend the application of the spectral element method (SEM) to wave propagation and free vibration analysis of functionally graded (FG) plates integrated with thin piezoelectric layers, plates with tapered thickness and structure on elastic foundations. Also, the dynamic response of the smart FG plate under impact and moving loads is presented. In this paper, the dynamic stiffness matrix of the smart rectangular FG plate is determined by using the exact dynamic shape functions based on Mindlin plate assumptions. The low computational time and results' independence with the number of elements are two significant features of the SEM. Also, to prove the accuracy and efficiency of the SEM, results are compared with Abaqus simulations and those reported in references. Furthermore, the effects of boundary conditions, power-law index, piezoelectric layers thickness, and type of loading on the results are studied.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1996.09a
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• pp.95-110
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• 1996

High Tensile Steel enables to reduce the plate thickness comparing to the case when Mild Steel is used. From the economical view point this is very preferable since the reduction in the hull weight. However to use the High Tensile Steel effectively the plate thickness may become thin so that the occurrence of buckling is inevitable and design allowing plate buckling may be necessary. If the inplane stiffness of the plating decreases due to buckling, buckling may be necessary. If the inplane stiffness of the plating decreases due to buckling the flexural rigidity of the cross section of a ship's hull also decreases. this may lead to excessive deflection of the hull girder under longitudinal bending. In these cases a precise estimation of plate's behavior after buckling is necessary and nonlinear analysis of isolated and stiffened plates is required for structural system analysis. In this connection this paper discusses nonlinear behaviour of thin plate under thrust. Based on the analytical method elastic large deflection analysis of isolated plate is perform and simple expression are derived to evaluate the inplane rigidity of plates subjected to uniaxial compression.

• Structural Engineering and Mechanics
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• v.68 no.6
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• pp.661-675
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• 2018

In this paper, buckling analysis of hybrid functionally graded plates using a novel four variable refined plate theory is presented. In this theory the distribution of transverse shear deformation is parabolic across the thickness of the plate by satisfying the surface conditions. Therefore, it is unnecessary to use a shear correction factor. The variations of properties of the plate through the thickness are according to a symmetric sigmoid law (symmetric S-FGM). The principle virtual works is used herein to extract equilibrium equations. The analytical solution is determined using the Navier method for a simply supported rectangular plate subjected to axial forces. The precision of this theory is verified by comparing it with the various solutions available in the literature.

• Structural Engineering and Mechanics
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• v.4 no.5
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• pp.541-552
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• 1996

This paper is concerned with the structural optimization problem of maximizing the compressive buckling load of orthotropic rectangular plates for a given volume of material. The optimality condition is first derived via variational calculus. It states that the thickness distribution is proportional to the strain energy density contrary to popular claims of constant strain energy density at the optimum. An engineers physical meaning of the optimality condition would be to make the average strain energy density with respect to the depth a constant. A double cosine thickness varying plate and a double sine thickness varying plate are then fine tuned in a one parameter optimization using the Rayleigh-Ritz method of analysis. Results for simply supported square plates indicate an increase of 89% in capacity for an orthotropic plate having 100% of its fibers in $0^{\circ}$ direction.

• Journal of the Korean Society of Safety
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• v.6 no.1
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• pp.5-13
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• 1991

Fail-safe design of machine elements or structural members is very aim of the whole mankind. Fracture occurs generally from cracks that exist originally or produced from flaws. The most important job we have to do is to make stopping or decreasing the crack growth rate. For fail-safe design variable thickness plates have been used as structural members in practical engineering services. In this paper, optimum design of CT type plate with varlng thickness is studied with the theoritical analysis. The theoritical analysis was based on the stress concentration and nominal stress analysis. From the study, the optimum design curve was determined for use of designing of such structures using the computer analysis program of optimum design.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.5
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• pp.150-156
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• 1997

Three dimensional finite element analysis was conducted to estimate the effect of shape parameters (plate width and thickness) on the stress intensity factor for crack in the integrally stiffened plate. Analysis was done for width ratios of 0.5, 0.75, 1.0, 1.5, 2.0, 2.5, and thickness ratios of 2, 3, 4, 6. Based on these results, an empirical equation of geometry factor is formulated as a function of crack length and thickness ratio.