• Proceedings of the KSME Conference
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• 2004.04a
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• pp.410-414
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• 2004

Under longitudinal loading continuous fiber reinforced metal matrix composite(MMC) have interpreted an outstanding performance. However, the applicability of continuous fiber reinforced MMCs is somewhat limited due to their relatively poor transverse properties. Therefore, the transverse properties of MMCs are significantly influenced by the properties of the fiber/matrix interface. In this study, elastic-plastic behavior of transversely loaded unidirectional fiber reinforced metal matrix composites investigated by using elastic-plastic finite element analysis. Different fiber placement(square and hexagon) and fiber volume fractions were studied numerically. The interface was treated as three thin layer (with different properties) with a finite thickness between the fiber and the matrix. The analyses were based on a two-dimensional generalized plane strain model of a cross-section of an unidirectional composite by the ANSYS finite element analysis code.

• Steel and Composite Structures
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• v.32 no.5
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• pp.657-670
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• 2019

This paper proposes a one-dimensional fiber beam element model taking account of materially non-linear behavior, benefiting the highly efficient elastic-plastic analysis of girders with shear-lag effects. Based on the displacement-based fiber beam-column element, two additional degrees of freedom (DOFs) are added into the proposed model to consider the shear-lag warping deformations of the slabs. The new finite element (FE) formulations of the tangent stiffness matrix and resisting force vector are deduced with the variational principle of the minimum potential energy. Then the proposed element is implemented in the OpenSees computational framework as a newly developed element, and the full Newton iteration method is adopted for an iterative solution. The typical materially non-linear behaviors, including the cracking and crushing of concrete, as well as the plasticity of the reinforcement and steel girder, are all considered in the model. The proposed model is applied to several test cases under elastic or plastic loading states and compared with the solutions of theoretical models, tests, and shell/solid refined FE models. The results of these comparisons indicate the accuracy and applicability of the proposed model for the analysis of both concrete box girders and steel-concrete composite girders, under either elastic or plastic states.

• Journal of the Korea Institute of Building Construction
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• v.2 no.3
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• pp.131-138
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• 2002

The objective of the study is to examine the characteristic correlations between reinforcing carbon fiber and interfacial adhesion agent since the interfacial adhesion strength between reinforcing carbon fiber and matrices is believed to be an essential element influencing the physical properties in carbon fiber reinforced cement composite using slurry method. The integrity of interfacial adhesion between reinforcing fiber and cement not only affects the quality of fiber reinforced cement composite but also influences to a large degree the physical properties of the cement composite when producing carbon fiber reinforced cement composite using slurry method. Having analyzed the physical properties 1.e., water content, tensile strength, flexural strength and flexural toughness of carbon fiber reinforced cement composite specimens, C-PAM(cation polyacrylamide) was determined to be an optimum interfacial adhesion agent. The study has also demonstrated that interfacial adhesion strength varies largely on the content and type of the reinforcing fiber. Judging from magnified view of the tensile shear cross-section using VMS(video microscope system), interfacial adhesion strength between reinforcing fiber and matrices is affected by the type of interfacial adhesion agent. According to the result of the experiments, C-PAM was determined to be an ideal interfacial adhesion agent when using carbon fiber in producing carbon fiber reinforced cement composite with the optimum content of carbon fiber being established.

• Journal of Mechanical Science and Technology
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• v.18 no.2
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• pp.221-229
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• 2004

In this work, an elastic-plastic stress analysis has been conducted for silicon carbide fiber reinforced magnesium metal matrix composite beam. The composite beam has a rectangular cross section. The beam is cantilevered and is loaded by a single force at its free end. In solution, the composite beam is assumed perfectly plastic to simplify the investigation. An analytical solution is presented for the elastic-plastic regions. In order to verify the analytic solution results were compared with the finite element method. An rectangular element with nine nodes has been choosen. Composite plate is meshed into 48 elements and 228 nodes with simply supported and in-plane loading condations. Predictions of the stress distributions of the beam using finite elements were overall in good agreement with analytic values. Stress distributions of the composite beam are calculated with respect to its fiber orientation. Orientation angles of the fiber are chosen as $0^{circ},\;30^{circ},\;45^{circ},\;60^{circ}\;and\;90^{circ}$. The plastic zone expands more at the upper side of the composite beam than at the lower side for $30^{circ},\;45^{circ}\;and\;60^{circ}$ orientation angles. Residual stress components of ${\sigma}_{x}\;and \;{\tau}_{xy}$ are also found in the section of the composite beam.

• Composites Research
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• v.12 no.6
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• pp.31-42
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• 1999

In aerospace industry, the improvement of structural performance of fight structure without increasing weight has great advantage. In this study. an innovative design method to increase the buckling load and tension failure load at the same time without increasing the weight of composite plates was investigated. By using the curvilinear fiber format a method to increase the buckling load and tension failure load simultaneously was investigated for composite plates with central hole with finite element method. It was investigated how much gain can be obtained with curvilinear fiber format for the plates with different hole size and different stacking sequence. And, for the cases studied, the failure mechanism was also investigated. For the manufacturing of the curvilinear fiber format, smoothly and continuously changing fiber path is necessary. In this study, a simple method to find the smoothly changing fiber path by using the fiber angles obtained with finite element method was presented.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.29 no.1
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• pp.61-65
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• 2016

Composites are materials that are widely used in industries such as automobile and aircraft. The composite material is required as a material for using in a high temperature environment as well as acting as a high pressure environment like the nozzle part of the ship. It is important to know the properties of composites. Result values obtained substituting the properties of matrix and fiber numerically have an large error compared with experimental value. In this study we utilize CASADsolver EDISON program for using Finite Element Method. Properties by substituting the fiber and Matrix properties of the composite material properties were compared with those measured in the experiment and calculated by the empirical properties.

• Composites Research
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• v.34 no.2
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• pp.129-135
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• 2021

In this paper, in order to examine the effect of fiber volume fraction non-uniformity in thickness direction on the buckling load of cylindrical composite lattice structures, we modified the equation of buckling load of the cylindrical composite lattice structures proposed by Vasiliev. The thickness of each layer of the rib was varied by fiber volume fraction, and material properties were applied differently by using the rule of mixture. Also, we performed linear buckling analysis by varying the structure size, thickness, and average value of the fiber volume fraction of finite element model. Finally, by comparing the calculation results of the buckling load of the equivalent model using the modified buckling load equation and the results of the finite element analysis, we found that the fiber volume fraction non-uniformity in thickness direction can reduce the buckling load of the cylindrical composite lattice structure.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2003.10a
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• pp.150-153
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• 2003

Longitudinal strains({$varepsilon}_x$) of the core and skin layers in glass fiber reinforced plastic(GFRP) cross-ply composite laminates have been studied using the embedded optical fiber sensor of totally-reflected extrinsic Fabry-Perot interferometer(TR-EFPI). Foil-type strain gauges bonded on both the upper and lower surfaces were used for the measurement of the surface strains. Both TR-EFPI sensor and strain gauge bonded on the specimen surface showed excellent agreement within -0.0086 ~ +0.0302% strain. It was shown that values of {$varepsilon}_x$ in the interior of the surface layer and the core layer measured by embedded TR-EFPI sensor was significantly higher than that of the specimen surface measured by strain gauges. The experimental results were ascertained with finite element analysis. Embedded TR-EFPI optical fiber sensor could measure accurately the internal strains which were different from the surface.

• Journal of Aerospace System Engineering
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• v.13 no.4
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• pp.10-17
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• 2019

This study is concerned with a numerical analysis based on the finite element method to describe the effect of midplane delamination in smart laminated composite plate structures. A new finite element model for centrally located delamination and healthy section was developed and coded in Matlab. The transient analysis of delaminated composite plate with integrated Active Fiber Composite (AFC) was investigated in the present article. The formulation of the governing equation was based on the minimum total potential energy approach. The Newmark time integration technique was employed to solve the differential equations. A parametric study on the effects of boundary conditions and AFC patch location, in presence of delamination on the laminated plate were studied.

• Journal of Mechanical Science and Technology
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• v.16 no.5
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• pp.666-675
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• 2002

Piezoelectric Fiber Composites with Interdigitated Electrodes (PFCIDE) were previously introduced as an alternative to monolithic wafers with conventional electrodes for applications of structural actuation. This paper is an investigation into the performance improvement of piezoelectric fiber composite actuators by changing the matrix material. This paper presents a modified micro-electromechanical model and numerical analyses of piezoelectric fiber/piezopolymer matrix composite actuator with interdigitated electrodes (PFPMIDE). Various concepts from different backgrounds including three-dimensional linear elastic and dielectric theories have been incorporated into the present linear piezoelectric model. The rule of mixture and the modified method to calculate effective properties of fiber composites were extended to apply to the PFPMIDE model. The new model was validated when compared with available experimental data and other analytical results. To see the structural responses of a composite plate integrated with the PFPMIDE, three-dimensional finite element formulations were derived. Numerical analyses show that the shape of the graphite/epoxy composite plate with the PFPMIDE may be controlled by judicious choice of voltages, piezoelectric fiber angles, and elastic tailoring of the composite plate.