• Journal of the Society of Naval Architects of Korea
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• v.29 no.2
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• pp.115-122
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• 1992

A sandwich element is a special Hybrid structural form of the composite construction, which is consisted of three main parts : thin, stiff and relatively high density faces separated by a thick, light, and weaker core material. In a sandwich construction, the shear deformation of the faces. Therefore, in the calculation of the bending stiffness, the shear effect should be included. In this paper, the minimum weight is selected as an object function, as the weight critical structures are usually composed of these kind of construction. To obtain the minimum weight of sandwich panel, the principle of minimum potential energy is used and as for the design constraints, the allowable bending stress of face material, the allowable shear stress of core material, the allowable value of panel deflection and the wrinkling stress of faces are adopted, as well as the different boundary conditions. For the engineering purpose of sandwich panel design, the results are tabulated, which are calculated by using the nonlinear optimization technique SUMT.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1553-1556
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• 2003

As the public use part of the railway and the road, the railway crossing is important to work properly by two transportation means. Also, It is important to provide the good face of friction on the railway crossing in aspect of protecting the railway crossing accident. Lately, the material of railway crossing panel is the wood. the asphalt, and the steel. As they have a various fault, it was studied to analyze the structural action of the new material. rubber panel. This paper analyzed eigenvalue, stress and displacement by truck passing weight and thermal stress using the FEM model.

• Transactions of Materials Processing
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• v.24 no.6
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• pp.400-404
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• 2015

For mass production of stamped parts, which require complicated in-press operations, it is always advisable to use a progressive die set. It is difficult to choose a progressive die set if the stamped parts need to be deep drawn and especially if they are unsymmetrical. Because unsymmetrical deep drawing parts are very sensitive to the effect of weight during moving to the next step, they are hard to exactly locate on the die face. An automotive seat side cushion panel is about 80mm high, unsymmetrical and its low edge needs hemming, so it is hard to produce even using a progressive die set. In the current paper a progressive stamping for seat side cushion panel was examined. Five strip bridges were considered to be strong enough to move to the next die as predicted by the CAE analysis.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.2
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• pp.228-233
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• 2002

TWB(Tailor Welded Blanks) is one of the recent techniques to reduce the weight and cost of the body members. To apply the TWB technique, we must decide the position of the welding line and the thickness of the welded blanks. Although many researchers have tried to check the formability of welded blanks, there are not so many researches from the structural point of view. In this paper, the TWB technique is applied to combine the door inner panel and the hinge face panel into one piece. The finite element structural analysis of the door assembly leads to the final design of the tailor welded door inner panel, which shows the mass reduction of 1.08kg without the sacrifice of the structural stiffness. The structural stiffness analysis includes the frame stiffness analysis, the belt line stiffness analysis, the door sagging analysis and the vibration analysis.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05a
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• pp.175-178
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• 2005

The major object of this paper is to propose a nonlinear finite element analysis(FEA) technique of steel coupling beams-wall connections governed panel shear failure using ABAQUS. Detailed finite element models are created by studying the monotonic load response of the designed steel coupling beams-wall connections. The developed models account for the effect of material inelasticity, concrete cracking, panel shear failure and geometric nonlinearity. In order to verify the proposed FEA model, this study attended experiment considered parameters to the steel beam : face bearing plates, and horizontal ties. And the analytical result attended by the proposed FEA model validated through comparisons with the experimental results. Finally, the study estimated the analytical values compared with ASCE Design Guidelines. At this time, the analysis showed good agreement between the theoretical and experimental results.

• Journal of the Korean Society for Railway
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• v.5 no.2
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• pp.125-132
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• 2002

As the public use part of the railway and the road, the railway crossing is important to work properly by two transportation means. Also, It is important to provide the good face of friction on the railway crossing in aspect of protecting the railway crossing accident. Lately, the material of railway crossing panel is the wood, the asphalt, and the steel. As they have a various fault, it was studied to analyze the structural action of the new material, rubber panel. This paper analyzed eigenvalue, stress and displacement by truck passing weight, thermal stress and train moving weight, using the Finite Element Method model

• Structural Engineering and Mechanics
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• v.83 no.3
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• pp.283-292
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• 2022

A nonlinear vibrational analysis of sandwich curved panels having multi-scale face sheets has been performed in this article based on differential quadrature method (DQM). All mechanical properties of multi-scale skins have been established in the context of three-dimensional Mori-Tanaka scheme for which the influences of glass fibers and random carbon nanotubes (CNTs) have been taken into account. The governing equations for sandwich the panel have been developed based upon thin shell formulation in which geometry nonlinearities have been taken into account. Next, DQ approach has been applied to solve the governing equations for determining the relationships of frequencies with deflections for curved panels. It will be demonstrated that the relationships of frequencies with deflections are dependent on the changing of CNT weight fractions, fibers alignment, fibers volume, panel radius and skin thickness.

• International Journal of Automotive Technology
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• v.7 no.7
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• pp.853-858
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• 2006

The method of die-face design based on the CAE platform for automobile panels can fast modify the die addendum. In contrast with the process of the die-face design based on the CAD platform, there are some special steps for the die-face design based on the CAE platform. The most obvious difference is that the auto-body part contour needs smoothing arlier than the design of addendum surfaces does. It is helpful to improve the design quality of addendum surface. In spite of extensive researches on the smoothing technique, here is still dearth of the published solutions about smoothing the part contour with additional surface. This paper attempts to analyze the difficulties and provides practical solutions. Main results include the algorithm to calculate the segments needing to be smoothed on boundary, the strategy to create the smoothing curve and the procedure of surface generation. The relevant function modules for parametric design are developed. A few examples and suggestions for future work conclude the paper.

• Journal of the Korean Wood Science and Technology
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• v.18 no.4
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• pp.86-101
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• 1990

The primary objective of this research was to investigate the strength properties of Comply, a composite panel. fabricated with particle board as core material and veneer or plywood as face and back. 20types of comply composites were manufactured according to the four specific gravity levels(0.5, 0.6, 0.7 or 0.8) of particleboard core and three veneer or two plywood thicknesses for face and back. They were tested and compared with matching particleboard (control) on moisture content. specific gravity, bending properties(MOE, MOR SPL). nail resistance and internal bond strength. The obtained results were summarized as follows: The increasing effect of modulus of elasticity was shown by the increase of face and back veneer or plywood thickness. The modulus of rupture and stress at proportional limit of the comply composites bonded with 3mm thick veneers or 3mm thick plywood face and back were higher than 2mm thick veneer or 2mm thick plywood as face and back. Both of modulus of rupture and stress at proportional limit on bending of Comply were higher than those of control board. Also the modulus of elasticity of Comply showed much higher than that of control board. The nail resistance of Comply, composed of plywood as face and back was higher than that of veneer. The nail resistance of control board was higher than that of Comply at Sp.Gr 0.7 and 0.8 core boards. Internal bond of Comply, composed of 1mm and 2mm thick veneer as face and back was higher than that of 3mm thick veneer. The increasing effect of modulus of elasticity was shown by the increase of shelling ratio in Comply composed of veneer and plywood as face and back. The modulus of rupture was increased by the increment of shellmg ratio in Compiy, composed of plywood as face and back. The modulus of elasticity and modulus of. rupture of comply were higher than those of particleboard(control) in effect of shelling ratio. Therefore it was concluded that the mechanical property values of Comply were clearly greater than those of particleboard(control).

• Journal of Ocean Engineering and Technology
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• v.33 no.6
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• pp.535-546
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• 2019

The paper presents a closed-form analytical solution for the ultimate strength of sandwich panels with metal faces and an elastic isotropic core during combined in-plane compression and lateral pressure under clamped boundary condition. By using the principle of minimum potential energy, the stress distribution in the faces during uni-axial edge compression and constant lateral pressure was obtained. Then, the ultimate edge compression was derived on the basis that collapse occurs when yield has spread from the mid-length of the sides of the face plates to the center of the convex face plates. The results were validated by nonlinear finite element analysis. Because the solution is analytical and closed-form, it is rapid and efficient and is well-suited for use in practical structural design methods, including repetitive use in structural optimization. The solution applies for any elastic isotropic core material, but the application that stimulated this study was an elastomer-cored steel sandwich panel that had excellent energy absorbing and protective properties against fire, collisions, ballistic projectiles, and explosions.