• Proceedings of the KSME Conference
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• 2008.11a
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• pp.518-522
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• 2008

Recently, many patients related to heart disease have surgical operation by expanding a blood vessel to treat the angiostenosis. So far most angioplasties have been performed using balloon-dilative stent made of stainless steel. Some researchers are studying the stent made of shape memory alloy (SMA) to operate the angioplasty more easily. and there are several papers which introduce the angioplasty using SMA. However, most of the analysis models for stents are constructed using solid elements. So much computing time is required to solve the analysis model. In this study, we suggest the SMA stent model using 1D truss element which is much faster than stent model using 3D solid element. To represent non-linear behavior of SMA, we apply 1D SMA constitutive equation of Lagoudas'. Pseudo-elastic behavior of stent structures is presented as a numerical example.

• Proceeding of KASS Symposium
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• 2005.05a
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• pp.167-172
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• 2005

In the dynamic analysis of cable structures, geometrical non-linearity due to the flexibility of cables must be considered efficiently. In this paper, formulation of tangent stiffness matrix of elastic catenary cable is derived by using relative nodal displacements, self-weight and unstressed cable length. Free vibration analysis of simply supported cable using elastic catenary cable elements is conducted and compared with that using truss elements. The result shows that elastic catenary cable elements are more compatible than truss elements in the case of analysis of cable structures. Furthermore, the characteristic of dynamic behaviors of cable structures by temporary unstability phenomenon is confirmed.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1993.04a
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• pp.117-124
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• 1993

The Neumann Expansion method has been used for evaluating the response variability of three dimensional truss structure resulting from the spatial variability of material properties with the aid of the finite element method, and in conjunction with the direct Monte Carlo simulation methods. The spatial variabilites are modeled as three-dimensional stochastic field. Yamazaki 〔1〕 has extended the Neumann Expansion method to the plane-strain problem to obtain the response variability of 2 dimensional stochastic systems. This paper presents the extension of the Neumann Expansion method to 3 dimensional stochastic systems. The results by the NEM are compared with those by the deterministic finite element analysis and by the direct Monte Carlo simulation method

• Journal of Korean Association for Spatial Structures
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• v.7 no.2 s.24
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• pp.75-82
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• 2007

Building costs means capital costs which include cost of land, cost of acquiring and preparing the site, construction costs, engineering fees, furnishings, cost of financing the project, and cost of management required to run and maintenance the building for use. An economic analysis is one of the most important factor to determine the project feasibility. The purpose of the this study is to analysis on the construction cost structure of steel truss stadium.

• Journal of Ocean Engineering and Technology
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• v.18 no.6 s.61
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• pp.51-57
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• 2004

In this study, the improved three-dimensional analysis model designed for a more accurate analysis of marine cable-supported structures, is presented. In this improved analysis model, the beam elements, of which the stability function is derived using Taylor's series expansions, are used to model space frame structures, and the truss elements. The equivalent elastic modulus of the truss elements is evaluated on the assumption that the deflection curve of a cable has a catenary function. By using the proposed three-dimensional analysis model, nonlinear static analysis is carried out for some cable-supported structures. The results are compared with previous studies and show good agreement with their findings.

• Journal of the Korea Concrete Institute
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• v.18 no.2 s.92
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• pp.177-188
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• 2006

Conventional nonlinear finite element analysis requires complicated modeling and analytical technique. Furthermore, it is difficult to interpret the analytical results presented as the stress-strain relationship. In the present study, a design-oriented analytical method using the truss model was developed. A reinforced concrete member to be analyzed was idealized by longitudinal, transverse, and diagonal line elements. Basically, each element was modeled as a composite element of concrete and re-bars. Simplified cyclic models for the concrete and re-bar elements were developed. RC beams and walls with various reinforcement details were analyzed by the proposed method. The inelastic strength, energy dissipation capacity, deformability, and failure mode predicted by the proposed method were compared with those of existing experiments. The results showed that the proposed model accurately predicted the strength and energy dissipation capacities, and to predict deformability of the members, the compression-softening model used for the concrete strut element must be improved.

• Journal of Korean Society of Steel Construction
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• v.23 no.1
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• pp.13-27
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• 2011

This paper presents an investigation of the structural stability of cable-stayed bridges, using geometric nonlinear finite-element analysis and considering various geometric nonlinearities, such as the sag effect of the cables, the beam-column effect of the girder and mast, and the large displacement effect. In this analytic research, a nonlinear frame element and a nonlinear equivalent truss element were used to model the girder, mast, and cable member. The live-load cases that were considered in this research were assumed based on the traffic loads. To perform reasonable analytic research, initial shape analyses in the dead-load case were performed before live-load analysis. In this study, the geometric nonlinear responses of the cable-stayed bridges with different cable arrangement types were compared. After that, parametric studies on the characteristics of the structural stability in critical live-load cases were performed considering various geometric parameters, such as the cable arrangement type, the stiffness ratios of the girder and mast, the area of the cables, and the number of cables. Through this parametric study, the effect of geometric shapes on the structural stability of cable-stayed bridges was investigated.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2008.04a
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• pp.45-48
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• 2008

Periodic lattice structures such as the large space lattice structures and carbon nanotubes may take the extension-transverse shear-bending coupled vibrations, which can be well represented by the extended Timoshenko beam theory. In this paper, the spectrally formulated finite element model (simply, spectral element model) has been developed for extended Timoshenko beams and applied to some typical periodic lattice structures such as the armchair carbon nanotube, the periodic plane truss, and the periodic space lattice beam.

• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.260-263
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• 1987

In this study, PC-based FEA system (Micro-STANS) running on the 16 bit microcomputer is developed. This system has powerful pre & post processing function using computer graphics, and is interfaced to AutoCAD system which is most popular PC-CAD system, making it possible to accomplish the concept of real integration between design and analysis. This system which has truss , beam plate & shell elements in the element library, can perform linear static analysis.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1403-1406
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• 2008

Periodic lattice structures such as the large space lattice structures and carbon nanotubes may take the extension-transverse shear-bending coupled vibrations, which can be well represented by the extended Timoshenko beam theory. In this paper, the spectrally formulated finite element model (simply, spectral element model) has been developed for extended Timoshenko beams and applied to some typical periodic lattice structures such as the armchair carbon nanotube, the periodic plane truss, and the periodic space lattice beam.