• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.152-153
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• 2015

Recently, solar energy generation is one of the fastest growing industries for eco-friendly energy. Every year, solar energy generation industry grows to 42% on average. However, polysilicon sludge is generated from processing of polysilicon but, there is nothing to handle that. Therefore, we need research to recycle polysilicon sludge. Also, improved fire resistance efficiency of wall is required according to reinforced fire safety standards due to many cases of big fires in our country. This study focuses on density and strength properties according to the addition ratio of paper Ash for the lightweight composite panel core with polysilicon sludge. As a result of the test, adding paper ash 9% has the best density and strength properties.

• Proceedings of the KSR Conference
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• 2002.10a
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• pp.182-187
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• 2002

Since most of main noise sources of the railroad vehicle are transmitted to the passenger's ear through the vibration of the panel, the insulation performance of the panels should be high enough to protect the passengers from the noisy environment. Specifically, the composite materials which are generally used for reducing the weight of the vehicle compartment have the low insulation performance, noise control actions should be taken appropriately by considering the insulation performance of the panels. In this study, the insulation performances of the inner/outer panels were evaluated and the contribution of the aluminum door was estimated compared to the composite panels. The results can furnish an indepth understanding of the insulation characteristics of the panel of railroad vehicle.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5A
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• pp.433-445
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• 2009

The panels are used as a composite part of the completed deck. They replace the main bottom transverse deck reinforcement and also serve as a form surface for the cast-in-place concrete upper layer that contains the top of deck reinforcement. Research has also demonstrated that mechanical shear ties on the top of the panels are required. In a composite deck with precast panels, it is required to notice behavior of transverse joints between panels. In this paper, static tests of composite deck with shear ties and loop joints were conducted. From the results, the validity of loop joints for continuity of deck was observed. Also, a composite behavior was abserved between precast panel and slab concrete. Tested composite decks with shear ties have 140~164% ultimate strength than have no shear ties due to the increase of composite action. Therefore, the shear ties between the slabs were sufficient to enforce composite flexural behavior to failure.

• Smart Structures and Systems
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• v.9 no.6
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• pp.505-534
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• 2012

The present work deals with second order statistics of post buckling response of piezoelectric laminated composite cylindrical shell panel subjected to hygro-thermo-electro-mechanical loading with random system properties. System parameters such as the material properties, thermal expansion coefficients and lamina plate thickness are assumed to be independent of the temperature and electric field and modeled as random variables. The piezoelectric material is used in the forms of layers surface bonded on the layers of laminated composite shell panel. The mathematical formulation is based on higher order shear deformation shell theory (HSDT) with von-Karman nonlinear kinematics. A efficient $C^0$ nonlinear finite element method based on direct iterative procedure in conjunction with a first order perturbation approach (FOPT) is developed for the implementation of the proposed problems in random environment and is employed to evaluate the second order statistics (mean and variance) of the post buckling load of piezoelectric laminated cylindrical shell panel. Typical numerical results are presented to examine the effect of various environmental conditions, amplitude ratios, electrical voltages, panel side to thickness ratios, aspect ratios, boundary conditions, curvature to side ratios, lamination schemes and types of loadings with random system properties. It is observed that the piezoelectric effect has a significant influence on the stochastic post buckling response of composite shell panel under various loading conditions and some new results are presented to demonstrate the applications of present work. The results obtained using the present solution approach is validated with those results available in the literature and also with independent Monte Carlo Simulation (MCS).

• Composites Research
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• v.22 no.4
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• pp.20-26
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• 2009

In the current study, thermoforming and compression analysis were carried out for the woven composite egg-box panel with the non-orthogonal constitutive material model, which is proposed by Xue et al. The material model is implemented in commercial engineering software, LS-DYNA, with a user subroutine. Directional properties in non-orthogonal coordinates are determinedusing the deformation gradient tensor and the material modulus matrix in local coordinate is updated at eaeh corresponding time step. After the implemented non-orthogonal constitutive model is verified by the bias extension test, the egg-box panel simulations are performed. The egg-box panel simulations are divided into two categories: thermoforming (draping) and crushing. The finite element model for crushing analysiscan be obtained using the displacement result of thermoforming process.

• Steel and Composite Structures
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• v.36 no.5
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• pp.521-531
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• 2020

The behavior variation of concrete dam is investigated, based on a new method for analyzing the data model of concrete dam in service process for the limitation of wavelet transform for solving concrete dam service process model. The study takes into account the time and position of behavior change during the process of concrete dam service. There is no dependence on the effect quantity for overcoming the shortcomings of the traditional identification method. The panel data model is firstly proposed for analyzing the behavior change of composite concrete dam. The change-point theory is used to identify whether the behavior of concrete dams changes during service. The phase space reconstruction technique is used to reconstruct the phase plane of the trend effect component. The time dimension method is used to solve the construction of multi-transformation model of composite panel data. An existing 76.3-m-high dam is used to investigate some key issues on the behavior change. Emphasis is placed on conversion time and location for three time periods consistent with the practical analysis report for evaluating the validity of the analysis method of the behavior variation of concrete dams presented in this paper.

• Aerospace Engineering and Technology
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• v.9 no.1
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• pp.9-16
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• 2010

In this study, structural analyses were carried out on the composite sandwich panel which was tested under compression loading. In the structural analyses, three types of finite element modelling were considered and linear buckling analysis and nonlinear analysis were performed for each FE-model. Through the analyses, it was found that shell elements for face parts and solid elements for core part were appropriate for the better prediction of the buckling load of the panel. If the material failure of the face is critical than overall buckling of the sandwich panel, the use of one shell element through the thickness direction was suitable in the FE-model for the better predictions of failure location and failure load.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.2
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• pp.10-15
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• 2006

The optimal design for stiffened laminated composite cylindrical panels under axial compression was studied using linear and nonlinear deformation theories by finite difference energy methods. Various panel structures was made from Carbon/Epoxy USN125 prepreg and considered 3 types stiffeners. Optimal design analyses of panel structure are carried out by the nonlinear search optimizer, ADS. This optimal design results are compared to the FEM result using ANSYS.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.219-224
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• 2000

A research for development of composite body panel is in progress for lightening tare. Low specific weight LPMC (Low pressure molding compound) has advantages such as lightweight and resistance to dent and corrosion. In this study, tensile, bending and impact tests for the LPMC and SPRC35 (High tension steel plate) were carried out and compared. Although mechanical properties of SPRC35 are better than the LPMC, the LPMC satisfies basic requirements for car body panel. The high temperature exposed LPMC were degraded due to fiber-matrix debonding and deterioration of resin.

• Proceedings of the KAIS Fall Conference
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• 2001.05a
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• pp.103-107
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• 2001

This study is simulation about buckling behavior under axial compression which is cylindrical panel laminated USN125 and USN150 made by various winding angle. And also this study compare with linear and nonlinear FDEM theory, and FEM theory. To solve the objective function and the design variables, this study use the linear and nonlinear buckling theories or FDEM and nonlinear search optimum design method of ADS for minimum weight design on which stiffened laminated composite cylindrical panel with stiffener that R-type section.