• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.10a
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• pp.190-195
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• 1997

Recently it is increased by degrees to construct complex or large lattice type structures such as bridges, towers, cranes, and structures that can be used for space technology. In general, in order to analyze, these structures we have used the finite element method(FEM). In this method, however, it is necessary to use a large amount of computer memory and computation time because the FEM requires many degrees of freedom for solving dynamic problems for these structures. For overcoming this problem, the authors have developed the transfer dynamic stiffness coefficient method(TDSCM). This method is based on the concepts of the transfer and the synthesis of the dynamic stiffness coefficient which is related to force and displacement vector at each node. In this paper, the authors formulate vibration analysis algorithm for a complex and large lattice type structure using the transfer of the dynamic stiffness coefficient. And the validity of TDSCM demonstrated through numerical computational and experimental results.

• Proceedings of the KSME Conference
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• 2001.06e
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• pp.94-99
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• 2001

The numerical simulation of the particle dispersion in the vortical flows provides insight into the mechanism of particle-fluid interaction. The simulation results show that the mixing layers are characterized by the large-scale vortical structures undergoing pairing process. The particle dispersion is strongly influenced by the large-scale structures and the particle sizes. The analysis shows that the mixing layers grows like a step-function.

• Magazine of the Korea Concrete Institute
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• v.7 no.1
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• pp.97-108
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• 1995

• Proceeding of KASS Symposium
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• 2005.05a
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• pp.89-98
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• 2005

Membrane structures, a kind of lightweight soft structural system, are used for spatial structures. The material property of the membrane has strong axial stiffness, but little bending stiffness. Therefore membrane structures arc unstable structures initially. These soft structures need to be introduced initial stresses first because of its initial unstable state, and it happens large deformation phenomenon. To find the structural shape after large deformation caused by initial stiffness introduced, we need the shape analysis considering geometric nonlinearity in structural design procedure. In this study, we investigate into the stress concentration at crack of membrane structures. Therefore, using the nonlinear analysis program that NASS (Nonlinear Analysis for Spatial Structures) perform nonlinear analysis, and stress distribution for creak length investigate for using linear elastic fracture mechanics.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1993.10a
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• pp.149-156
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• 1993

Precast concrete (P.C.) large panel structures have usually weaker stiffness at joints than that of monolithic in-situ reinforced concrete structures. But structural designers do not in general take into account this characteristics of P. C. large panel structures and use the same analytical models as for the monolithic structure. Therefore, the results of analysis obtained by using these models may be quite different from those actually occuring in real P.C. structure. In this study, the change in force and stress distribution and deflections of structure caused by applying lower shear stiffness at vertical joints are investigated through trying several finite element modeling schemes specific for P.C. structures. Finally, for engineers in practice. a simplified model, which takes account of the effect of lower shear stiffness at vertical joints, is proposed with the understanding on possible amount of errors.

• Journal of Power System Engineering
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• v.1 no.1
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• pp.91-97
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• 1997

Recently, it is increased by degrees to construct complex and large structures. In general, in order to solve the dynamic problem of these structures they have used finite element method(FEM). In this method, however, it is necessary to prove whether its results are correct or not. Therefore it requires much effort, time and many expenses for dynamic analysis of complex and large structures. Authors have developed the transfer dynamic stiffness coefficient method(TDSCM) which is the new vibration analysis method for complex and large structures on personal computer, and confirmed that the results of this method are good for these structures on personal computer. In this paper, TDSCM is applied to the torsional vibration analysis for the shaft system which consist of concentrated disks and shafts of continuous body. First, we formulate algorithms for torsional free and forced vibration analysis, and compare the results of TDSCM and FEM.

• Journal of Korean Association for Spatial Structures
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• v.16 no.1
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• pp.105-113
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• 2016

Since the 1980s, the number of large space buildings in Korea has consistently been increasing due to large scale international competitions such as the Olympics and the World Cup, demands for environmental improvement, and development of structural systems. Due to these reasons, this paper conducted a comparative analysis on terrorism risk factors of large space structure and skyscrapers in Korea. The results suggest that the total risk level of high-rise and large space structure was "medium level risk" and that the terrorism risk level for large space structure was as high as that for high-rise buildings. As it relates to the risk levels depending on scenarios, terrorism risks to large space structure were higher than high-rise buildings in the "internal explosion" and "internal intrusion" categories. And the results of analyzing explosion-related scenarios except for CBR suggest that terrorism risks to large space structure were highest when it comes to Internal-Explosive followed by Internal-Intrusion and Explosive-Zone I; and the results showed a regular pattern. On the other hand, in the case of high-rise buildings, terrorism risks were highest in Internal-Explosive followed by Explosive-Zone I and Explosive-Zone II; and the results showed an irregular pattern.

• Journal of Korean Association for Spatial Structures
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• v.10 no.4
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• pp.67-74
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• 2010

Single layer latticed domes which have a mechanics property, a functional property, a aesthetic property and so on, occupies one part of long span space structures and after this, the using parts will be extended. The frame network pattern of single-layer latticed domes can be infinitely taken into account. The typical network patterns are triangular, square, hexagon, lamella and rib etc. It would take long time and cost too much to erect large roof structures with traditional erection techniques due to require of large number of temporary bracing and supports. The erection of large roof structures requires special techniques. As one of these special techniques is the Step-Up election method that utilizes jack-up supports and this will extremely saves time and cost to erect large roof structures. The objective of this study is to analysis the buckling characteristics of single-layer lamella domes according to the support number and position. From the result of this study, we obtained the fundamental data for the structural engineers who design the temporary support of large roof structures.

• Proceeding of KASS Symposium
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• 2005.05a
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• pp.125-132
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• 2005

Membrane structures, a kind of lightweight soft structural system, are used for spatial structures. The material property of the membrane has strong axial stiffness, but little bending stiffness. The design procedure of membrane structures are needed to do shape finding, stress-deformation analysis and cutting pattern generation. In shape finding, membrane structures are unstable structures initially. These soft structures need to be introduced initial stresses because of its initial unstable state, and it happens large deformation phenomenon. And also there are highly varied in their size, curvature and material stiffness. So, the approximation inherent in cutting pattern generation methods is quite different. Therefore, in this study, to find the structural shape after large deformation caused by Initial stress, we need the shape analysis considering geometric nonlinear ten And the geodesic line on surface of initial equilibrium shape and the cutting pattern generation using the geodesic line is introduced.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2008.04a
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• pp.374-379
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• 2008

The purpose of seismic isolation system among them is to lengthen the period of structure and make its period shift from the dominant period of earthquake. In this study, the seismic behavior of arch structure with lead rubber bearing(LRB) and friction pendulum system(FPS) is analyzed. The arch structure is the simplest structure and has the basic dynamic characteristics among large spatial structures. Also, Large spatial structures have large vertical response by horizontal seismic vibration, unlike seismic behavior of normal rahmen structures. When horizontal seismic load is applied to the large spatial structure with isolation systems, the horizontal acceleration response of the large spatial structure is reduced and the vertical seismic response is remarkably reduced.