• Proceedings of the Computational Structural Engineering Institute Conference
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• 2003.04a
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• pp.137-144
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• 2003

Since quasi-brittle material like concrete shows strain localization behavior accompanied by strain softening, a numerical drawback such as mesh sensitivity is appeared in the finite element analysis. In this study, a homogenized crack model which overcomes the drawback and considers rate discontinuity in the constitutive equation is proposed for modeling of cracking in concrete and its propagation in strain softening regime. Then, a series of finite element analysis of the concrete under various loading conditions has been performed. From comparison of analysis results with experimental data, it is shown that failure behavior due to localized cracking of concrete under both compressive loading condition and tensile loading condition is well predicted by the homogenized crack model.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1998.10a
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• pp.455-462
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• 1998

Analysis and design of vibrating machine foundations subjected to dynamic loads is a very complex problem. Thus it is difficult to set up an accurate analytical modeling. Generally, the design of foundations for vibrating machines has been performed by the equivalent static analysis which is generally based on engineer's experience and various assumptions The purpose of this study is to develop an integrated system which enables structural engineers to produce results of high quality within a short time in works related to structural analysis and design of foundation for vibrating machines. As the result of this study, level-up of application software is expected as well as improvement of quality in structural engineering and reduction of engineers' effort.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2002.10a
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• pp.131-138
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• 2002

The fuel handling machine handles the core assembly in refueling period of the reactor, it is necessary to predict the motion and structural integrity of it. The kinetic analysis of the fuel handling machine was carried out for the refueling motion. The reaction forces at the joints of machine were calculated with IDEAS code considering the weight of the machine and the loading force of the core assembly, Also, the structural analysis for the machine modeled by lumped-mass and beam elements was performed by using ANSYS code. The stresses and deformations were calculated for the equivalent static force based on the kinetic analysis and the seismic loads. The calculated displacements and stresses are quite low compared with allowable limits.

• Computational Structural Engineering
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• v.7 no.2
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• pp.111-120
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• 1994

Cracks in rubber bonded to a rigid material such as steel are analyzed with the aid of a mixed finite element technique. Firstly the weak form is derived for finite element analysis of an incompressible material, and the Mooney-Rivlin form is assumed for the constitutive modeling of rubber. The numerical results from finite element analysis is examined to confirm the accuracy and convergence of solution by way of comparison to other numerical results. The interpretation of the J-integral for large elastic deformation as the energy release rate is confirmed, and the J-integral is calculated for varing crack length. The crack growth stability is discussed using the result of finite element analysis.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2007.04a
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• pp.405-410
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• 2007

We present a new global/local analysis with the aid of MLS(Moving Least Square)-based finite elements which can handle an arbitrary number of nodes on every element side. It give a great flexibility in constructing finite element meshes at the specified local regions without remeshing. Compared to other type global/local analysis, it does not require any superimposed mesh or need not solve the equilibrium equation twice as well as shows an excellent accuracy. To demonstrate the performance of proposed scheme, we will show several examples in relation to capturing highly local stress field.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1997.04a
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• pp.71-78
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• 1997

The high precision analysis by the p-version of the finite element method are fairly well established as highly efficient method for linear elastic problems, especially in the presence of stress singularity. It has been noted that the merits of p-version are accuracy, modeling simplicity, robustness, and savings in user's and CPU time. However, little has been done to exploit their benefits in elasto-plastic analysis. In this paper, the p-version finite element model is proposed for the materially nonlinear analysis that is based on the incremental theory of plasticity, the associated flow rule, and von-Mises yield criteria. To obtain the solution of nonlinear equation, the Newton-Raphson method and initial stiffness method, etc are used. Several numerical examples are tested with the help of the square plates with cutout, the thick-walled cylinder under internal pressure, and the center cracked plate under tensile loading. Those results are compared with the there cal solutions and the numerical solutions of ADINA software.

• Journal of Power System Engineering
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• v.19 no.1
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• pp.38-44
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• 2015

Various finite elements have been studied and developed to analyze a variety of structures in the finite element method(FEM). The transfer stiffness coefficient method(TSCM) is an effective algorithm for structural analysis but the structures which can be applied were limited. In this paper, a computational algorithm for the structural analysis of axisymmetric conical shells under axisymmetric loading is formulated using the finite element-transfer stiffness coefficient method(FE-TSCM). The basic concept of FE-TSCM is the combination of the modeling technique of FEM and the transfer technique of TSCM. The FE-TSCM has all the advantages of both FEM and TSCM. After carrying out the structural analysis of axisymmetric conical shells using FEM, FE-TSCM, and analytical method we compare the computational results of FE-TSCM with those of the other methods in terms of computational accuracy.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.2 s.119
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• pp.105-113
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• 2007

In this study, three-dimensional rotordynamic analyses have been conducted using equivalent beam, hybrid and full three-dimensional models. The present computational method is based on the general finite element method with rotating gyroscopic effects of the rotor system. General purpose commercial finite element code, SAMCEF which includes practical rotordynamics module with various types of rotor analysis tools and bearing elements is applied. For the purpose of numerical verification, comparison study for a benchmark rotor model with support bearings is performed first. Detailed finite element models based on three different modeling concepts are constructed and then computational analyses are conducted for the realistic and complex three-dimensional rotor system. The results for rotor stability and mass unbalance response are presented and compared with the experimental vibration test data conducted herein.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.12 no.3
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• pp.363-370
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• 1999

This study presented an modeling method for the connections in mixed structure with reinforced concrete columns and steel beam using finite element method. The contacting surfaces between concrete and steel are modeled using master-slave contact algorithm and the incompatible mode elements were used in the steel tube subjected to bending. The characteristics of mixed structure was that diaphragm was used for transferring force from beam to column. The three dimensional nonlinear analysis was performed and the analytical results compared with experimental results in order to prove modeling method.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1989.04a
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• pp.38-43
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• 1989

An improved model for predicting the reinforced concrete element behavior under dynamic strain rates was developed using the layer modeling technique. The developed strain rate sensitive model for axial/flexural analysis of reinforced concrete elements was uses to predict the test results, performed at different loading rates, and the predictions were reasonable. The developed analysis technique was used to study the loading rate sensitivity of reinforced concrete beams and columns with different geometry and material properties. Two design formulas for computing the loading rate dependent axial and flexural strengths of reinforced concrete sections were also suggested.