• Proceedings of the Computational Structural Engineering Institute Conference
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• 1994.10a
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• pp.17-24
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• 1994

The pre- and post-processor for finite element structural analysis considering the user-friendly device are developed by using GUI. These can be used on WINDOWS' environment which is realized the multi-tasking and the concurrency by object-oriented paradigm. They are designed to control integratedly the pre-processing, execution and the post-processing of the finite element structural analysis program on multiple windows. These object-oriented modeling approach can be used for complex integrated engineering systems.

• Composites Research
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• v.30 no.6
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• pp.338-342
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• 2017

In this paper, evaluation method of structural integrity of cylindrical composite lattice structures was conducted. A finite element analysis was used to evaluate the structural integrity of composite lattice structures. In order to verify the optimal finite element in the evaluation of the structural integrity, finite element models for cylindrical composite lattice structure were generated using beam, shell and solid elements. The results of the finite element analyses with the shell and solid element models showed a good agreement. However, considerable differences were found between the beam element model and the shell and solid models. This occurred because the beam element does not take into account the degradation of the mechanical properties of the non-intersection parts of cylindrical composite lattice structures. It was found that the finite element analysis of evaluation of structural integrity for cylindrical composite lattice structures have to use solid element.

• Journal of Mechanical Science and Technology
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• v.15 no.5
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• pp.555-561
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• 2001

A new approach to analyze the multi-domain acoustic system divided and enclosed by flexible structures is presented in this paper. The boundary element formulation of the Helmholtz integral equation is used for the internal fields and the finite element formulation for the structures surrounding the fields. We developed a numerical analysis program for the structural-acoustic coupling problems of the multi-domain system, in which boundary conditions such as the continuity of normal particle velocity and sound pressure in the structural interfaces between Field 1 and Field 2 are not needed. The validity of the numerical analysis program is verified by comparing the numerical results with the experimental ones. Example problems are included to investigate the characteristics of the coupled multi-domain system.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2003.04a
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• pp.269-278
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• 2003

In this study, the method of the finite element modeling for free vibration control of beam-type smart structures with bonded plate-type piezoelectric sensors and actuators is proposed. Constitutive equations for the direct piezoelectric effect and converse piezoelectric effect of piezoelectric materials are considered. By using the variational principle, the equations of motion for the smart beam finite element are derived, The proposed 2-node beam finite element is an isoparametric element based on Timoshenko beam theory. Therefore, by analyzing beam-type smart structures with smart beam finite elements, it is possible to simulate the control of the structural behavior by applying voltages to piezoelectric actuators and monitoring of the structural behavior by sensing voltages of piezoelectric sensors. By using the smart beam finite element and constant-gain feed back control scheme, the formulation of the free vibration control for the beam structures with bonded plate-type piezoelectric sensors and actuators is proposed.

• Structural Engineering and Mechanics
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• v.54 no.3
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• pp.393-417
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• 2015

In this paper an 8-node quadrilateral assumed stress hybrid Mindlin plate element with $39{\beta}$ is presented. The formulation is based on complementary energy principle. The proposed element is free of shear locking and is capable of passing all the patch tests, especially the non-zero constant shear enhanced patch test. To accomplish this purpose, special attention is devoted to selecting boundary displacement interpolation and stress approximation in domain. The arbitrary order Timoshenko beam function is successfully used to derive the boundary displacement interpolation. According to the equilibrium equations, an appropriate stress approximation is rationally derived. Particularly, in order to improve element's accuracy, the assumed stress field is derived by employing $39{\beta}$ rather than conventional $21{\beta}$. The resulting element can be adopted to analyze both moderately thick and thin plates, and the convergence for the very thin case can be ensured theoretically. Excellent element performance is demonstrated by a wide of experimental evaluations.

• Magazine of the Korean Society of Agricultural Engineers
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• v.32 no.E
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• pp.59-66
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• 1990

Abstract The formulation of the probabilistic finite element method was briefly reviewed. The method was implemented into a computer program for frame analysis which has the same analogy as finite element analysis. Another program for Monte Carlo simulation of finite element analysis was written. Two sample structures were assumed and analized. The characteristics of the second moment statistics obtained by the probabilistic finite element method was examined through numerical studies. The applicability and limitation of the method were also evaluated in comparison with the data generated by Monte Carlo simulation.

• Structural Engineering and Mechanics
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• v.35 no.2
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• pp.175-190
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• 2010

One of the intractable problems in multiresolution structural analysis is the decoupling computation between scales, which can be realized by the operator-orthogonal wavelets based on the lifting scheme. The multiresolution finite element space is described and the formulation of multiresolution finite element models for structural problems is discussed. Various operator-orthogonal wavelets are constructed by the lifting scheme according to the operators of multiresolution finite element models. A dynamic multiresolution algorithm using operator-orthogonal wavelets is proposed to solve structural problems. Numerical examples demonstrate that the lifting scheme is a flexible and efficient tool to construct operator-orthogonal wavelets for multiresolution structural analysis with high convergence rate.

• Journal of the Society of Naval Architects of Korea
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• v.44 no.3 s.153
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• pp.314-322
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• 2007

In general, the vibration and structural analyses have been carried out by using each finite element model separately because of different size of finite element mesh and different focusing area of each analysis. In some cases, however, it is required to perform both global vibration and structural analyses at the same time using a finite element model for global structural analysis, which asks for a special treatment for a vibration analysis. In this study, a technique to perform a global vibration analysis using a finite element model for a global structural analysis has been developed and its effectiveness has been verified by its application to a whole ship.

• Journal of Aerospace System Engineering
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• v.6 no.2
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• pp.28-34
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• 2012

Structural integrity evaluation is important item in the aircraft certification. Recently, it is designed for limit load, material weakness about fatigue and corrosion, damage by bird strike in flight to evaluate structural integrity of aircraft. And static/fatigue analysis are performed to secure structural integrity, it was verified by static and fatigue tests. To evaluate the structural integrity of small aircraft tail, structural integrity was calculated by the finite element analysis. In the present study, finite element analysis are performed to pick out load cases in flight occurrence, and secure margin of safety to evaluate structural integrity of KC-100 tail unit. The proprieties of finite element analysis results are compared with the static structure test results. The estimation process of structural integrity for small aircraft tail may help the design.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.121-126
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• 2004

In this paper, a nonlinear structural damage identification algorithm is derived by taking into account the structurally damped spectral element model thinking over a real situation. The structural damage identification analyses are conducted by using the Newton-Raphson method. It is found that, in general Structural Damage Identification by using the Structurally Damped Spectral Element Model provides the same exact damage identification results when compared with the results obtained by the structurally undamped spectral model.