• Special Issue of the Society of Naval Architects of Korea
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• 2013.12a
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• pp.21-29
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• 2013

For the purpose of supporting Curved Blocks, pipe welding is commonly used on Curved panel. Typically, when it comes to attaching supporting pipe on heavy incurvated surface, it makes much loss in the process of design, cutting, welding. This paper gives proper methods to collecting problems and Core conflicts surrounding Support Pipe by using of TOC (Theory Of Constraints). Therefore drawing two solutions, pipe development program and NC generating from pipe development Data for Plate Cutting machine. It describes a process of erasing loss surrounding Support Pipe with "TOC Thinking process" and development of two programs in this paper.

• Smart Structures and Systems
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• v.26 no.5
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• pp.641-656
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• 2020

The finite element solutions of thermal buckling load values of the graded sandwich curved shell structure are reported in this research using a higher-order kinematic model including the shear deformation effect. The numerical buckling temperature has been computed using an in-house specialized code (MATLAB environment) prepared in the framework of the current mathematical formulation. In addition, the mathematical model includes the excess structural distortion under the influence of elevated environment via Green-Lagrange nonlinear strain. The corresponding eigenvalue equation has been solved to predict the critical buckling temperature of the graded sandwich structure. The numerical stability and the accuracy of the current solution have been confirmed by comparing with the available published results. Thereafter, the model is extended to bring out the influences of structural parameters i.e. the curvature ratio, core-face thickness ratio, support conditions, power-law indices and sandwich types on the thermal buckling behavior of graded sandwich curved shell panels.

• Journal of Welding and Joining
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• v.28 no.2
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• pp.39-46
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• 2010

IIn this study, used is the equivalent loading method based on the inherent strain to predict the welding deformation of panel members. Equivalent loads are computed from the inherent strain distribution around weld line, and then applied for the linear finite element analysis. Thermal deformation of panel members can be, of course, carried out through the rigorous thermal elasto-plastic analysis procedure but it is not practical in applying to predicting the welding deformation of large structures such as blocks found in a ship structure from view of computing time. The present equivalent load approach has been applied to flat plate model to verify the present approach, and to several curved plate models having the curvature in the welding direction to investigate the effect of the longitudinal curvature upon the weld-induced deformation. The results are compared with those by thermal elasto-plastic analysis. As far as the present results are concerned, it can be said that the present approach shows good agreement with the results by welding experiment and the rigorous thermal elasto-plastic analysis. The present approach has been also applied to predict the welding deformation of panel block as for application illustration to practical model.

• Steel and Composite Structures
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• v.22 no.6
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• pp.1359-1389
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• 2016

Buckling and free vibration behavior of a laminated cylindrical panel exposed to non-uniform thermal load is addressed in the present study. The approach comprises of three portions, in the first portion, heat transfer analysis is carried out to compute the non-uniform temperature fields, whereas second portion consists of static analysis wherein stress fields due to thermal load is obtained, and the last portion consists of buckling and prestressed modal analyzes to capture the critical buckling temperature as well as first five natural frequencies and associated mode shapes. Finite element is used to perform the numerical investigation. The detailed parametric study is carried out to analyze the effect of nature of temperature variation across the panel, laminate sequence and structural boundary constraints on the buckling and free vibration behavior. The relation between the buckling temperature of the panel under uniform temperature field and non-uniform temperature field is established using magnification factor. Among four cases considered in this study for position of heat sources, highest magnification factor is observed at the forefront curved edge of the panel where heat source is placed. It is also observed that thermal buckling strength and buckling mode shapes are highly sensitive to nature of temperature field and the effect is significant for the above-mentioned temperature field. Furthermore, it is also observed that the panel with antisymmetric laminate has better buckling strength. Free vibration frequencies and the associated mode shapes are significantly influenced by the non-uniform temperature variations.

• The Journal of the Acoustical Society of Korea
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• v.21 no.3E
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• pp.132-139
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• 2002

Swaging technique is frequently used to stiffen thin panels for reducing the vibration levels of the machine or vehicle structure. Because the internal constraints imposed by swages can distort the mode shapes of panels, they affect the sound radiation characteristics. In this paper, the radiated sound field generated by the idealized and baffled finite swaged panel is studied, in which the curved swage section is modeled as an incomplete cylindrical shell. The modal radiation efficiencies are predicted using the transfer matrix concept and compared with those of flat panels. It is observed that the radiation efficiencies of the swaged vibrational modes can increase slightly for frequencies below the critical frequency, while increase of radiation efficiency depends on the mode shapes and other related structural parameters.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.9
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• pp.782-787
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• 2008

First, the effect of the geometry such as the curved shape of the struts composing the truss structure of WBK is elaborated. Then, analytic solutions for the material properties of WBK and the maximum loads of a WBK-cored sandwich panel under bending are derived. A design optimization with the face sheet thickness and the core height selected as the design variables is presented for given slenderness ratios of the WBK core. Unless the face sheet thickness is limited, the optimal design to give the maximum load per weight is always found at a confluence of three failure modes, namely, face sheet yielding, indentation plastic, and core shear modeB plastic.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.83-84
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• 2019

Free-form buildings refer to geometric external structures in curved form, unlike conventional structures with straight lines. The development of construction technologies for the implementation of these Free-form buildings is ongoing. However, there are still many restrictions on the construction technology of Free-form buildings, resulting in problems such as increased construction period and increased construction costs. Therefore, it is urgent to develop building technology for the construction of Free-form building in order to secure competitiveness in the global Free-form building market. Accordingly, this study proposes Two-sided multi-point press technology that can solve problems of existing technology and implement FCP(Free-form Concrete Panel).

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.228-233
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• 2016

Auxetic material is a material which has negative Poisson's ratio(NPR). Auxetic material shows some distinctive property like high energy absorbing property and high shear modulus. Among these, synclastic curvature is very interesting characteristic. When synclastic-curvature-material bends, it changes its shape like dome, contrary to non-auxetic material which changes its shape like saddle(anticlastic). This distinctive property could make it easy to manufacture curved structure like nose cone or wing panel in aerospace engineering. In this study, we studied a quantitative analysis about synclastic curvature of re-entrant panel with finite element model. We suggested a concept 'Degree of Synclasticity(DOS)', which means a ratio of curvature of load-direction and load-orthogonal direction. We studied the variation of DOS with two factor, unit cell inner angle(${\theta}$) and load position angle(${\phi}$). DOS decreases as ${\theta}$ increases because the unit cell goes out of auxetic-shape. As ${\phi}$ varies, DOS changes in a large range. So proper optimization of ${\phi}$ would be needed for application.

• Earthquakes and Structures
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• v.16 no.1
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• pp.55-67
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• 2019

The finite solutions of deflection and the corresponding in-plane stress values of the graded sandwich shallow shell structure are computed in this research article via a higher-order polynomial shear deformation kinematics. The shell structural equilibrium equation is derived using the variational principle in association with a nine noded isoprametric element (nine degrees of freedom per node). The deflection values are computed via an own customized MATLAB code including the current formulation. The stability of the current finite element solutions including their accuracies have been demonstrated by solving different kind of numerical examples. Additionally, a few numerical experimentations have been conducted to show the influence of different design input parameters (geometrical and material) on the flexural strength of the graded sandwich shell panel including the geometrical configurations.

• Journal of the Korea institute for structural maintenance and inspection
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• v.8 no.2
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• pp.247-258
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• 2004

The composite shell element is developed for the solution of undamped forced vibration problem of composite curved panels. The finite element used in the current study is an 4-node enhanced assumed shell element with six degrees of freedom per node. The composite shell element is free of both shear and membrane locking phenomenon by using the enhanced assumed strain(EAS) method. A modification to the first-order shear deformation shell theory is proposed, which results in parabolic thorough-thickness distribution of the transverse shear strains and stresses. It eliminates the need for shear correction factors in the first order theory. Newmark's direct integration technique is used for carrying out the integration of the equation motion, to obtain the repones history. Parametric studies of curved composite panels are carried out for forced vibration analysis by geometrical shapes and by laminated composite; such as fiber orientation, stacking sequence.