• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.3 s.55
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• pp.209-216
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• 2009

Flexible frames on their own offer little resistance to lateral forces, resulting often in large deflections and rotations at the joints. On the other hand, walls subjected to lateral loads fail mainly in shear at relatively small displacements. Therefore, when the nonductile frames and wall act together, the combined action of the composite system differs significantly from that of the frame or wall alone. The objective of the study is to evaluate seismic response of infill walls with notched midsection. Reinforcement detail of wall was main variable in the experiment. Also SHCC was used in order to prevent damage concentration into notched midsection of walls. Test results, SHCC infill walls show the multiple crack patterns as expected. However, PIW-ND specimen exhibits less story drift, stiffness and energy dissipation capacity than those of PIW-NC specimen.

• Journal of the Korea institute for structural maintenance and inspection
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• v.9 no.2
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• pp.137-146
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• 2005

This study presents the shape iteration method and the updated Lagrangian methods to calculate the initial tension and the reference length of cables of cable-stayed bridges. The girders and towers of cable-stayed bridge are modelled as 3-dimensional frame elements and the cable as nonlinear truss element or Ernst's cable element. Compared with the initial tensions of cables by finite element method in this study and by trial-and error method in practices, the tensions by the former are shown to be a little less than the those by the latter. The reference lengths of cables by Ernst's cable elements are almost consistent with those of cables by nonlinear truss elements. And the reference length of cables in this study are almost consistent with the arc length of beam with the same initial tension. Therefore the reference lengths of cables in cable-stayed bridges are shown to be obtained simply by the theory of beam with the initial tension calculated in this study.

• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.4
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• pp.97-107
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• 2006

This study is structural analysis and continuous, discrete optimum design of braced steel frame structures under earthquake loads considering soil condition. The program which is able to perform simultaneously structural analysis and continuous, discrete optimum design, it is applied steel frame structures using unbraced, Z-braced, and X-braced types and analyze the program about static loads and seismic loads. The purpose of this study is to present proper braced type for seismic effects by comparing and analyzing results of analytic method about various cases using specially Newmark-Hall design spectrum, ATC design spectrum and ATC equivalent static analysis and finding minimum weight and design variables which satisfy the ultimate strength requirements of AISC-ASD specifications, the serviceability requirements and allowable story drift requirements of ATC-3-06 and various constraints.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.6
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• pp.84-91
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• 2019

For the goal of the proposal for optimum position of offset outrigger system, a structural schematic design of 70 stories building was carried out, using the general structure analysis program of MIDAS-Gen. In this research, the primary factors of this analysis research were the shear wall stiffness, the frame stiffness, the outrigger stiffness, the stiffness of column linked in outrigger system, etc. To achieve the aim of this study, we analyzed and studied the lateral displacement in top level, the force distribution of outrigger, the existing model of optimal outrigger location, and so on. This paper proposed the optimal position of offset outrigger system. Furthermore it is considered that the study results can be useful in getting the structure engineering data for seeking the optimal position of offset outrigger in the tall building.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.5
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• pp.108-116
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• 2017

In this study, the prototype structure of seismically designed steel moment frame was analyzed statically and dynamically in order to demonstrate the applicability of energy-based approximate analysis with the dynamic effect of sudden column loss in the evaluation of the collapse resistance and a method for assessing the sensitivity to progressive collapse was proposed. For the purpose of comparing the structural behavior of buildings with different structural systems, the sensitivity of the structure to the sudden removal of vertical members can be used as a significant measure. The energy-based approximate analysis prediction for the prototype structure considered in the study showed good agreement with the dynamic analysis result. In the sensitivity evaluation, the structural robustness index that indicates the ability of a structure to resist collapse induced by abnormal loads was used. It was confirmed that the proposed methods can be used conveniently and rationally in progressive collapse analysis and design.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.1
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• pp.1-9
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• 2013

In this study of Eccentric Braced Frames have identified the following target eccentricity on the length of the inelastic behavior of the reaction by calculating the correction factor by comparing it to the value suggested by the earthquake provided material for the rational design aims to There are. As a variable-length V-braced frame analysis model stations were set up. Eccentricity faults in the model according to the length stiffness ratio, the maximum amount of energy dissipation were analyzed base shear and multi-layered model of the reaction from the eccentricity correction factor calculated on the length of the building standards proposed by KBC 2009 in response eccentricity correction factor calculated from The length varies. does not have the same response modification factor was confirmed.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.2
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• pp.125-135
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• 2011

The latest study for formulation of finite element method and computation techniques has progressed widely. The classical method in the formulation of frame elements for geometrically nonlinear analysis derives the geometric stiffness directly from the governing differential equation for bending with axial force. From the computational viewpoint of this paper, the most common approach is the finite element method. Commonly, the formulation of frame elements for geometrically nonlinear structures is based on appropriate interpolation functions for the transverse and axial displacements of the member. The formulation of flexibility-based elements, on the other hand, is based on interpolation functions for the internal forces. In this paper, a new method is used to suppose that interpolation functions for the displacements from the curvatures is Lagrangian interpolation. This paper derives flexibility matrix from that displacement functions and is considered the application of it. Using the flexibility matrix, this paper apply the program considered geometrically nonlinear analysis to common problems.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.1
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• pp.107-114
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• 2018

In this study, the damage detection method is proposed for the rotational stiffness of connections in steel moment frames by using artificial neural network(ANN). The flexural moment of columns, natural frequencies, modeshapes are used for the input layer in ANN while the damage index, that signify the damage level, is used for the output layer in ANN. The 5-story steel moment frame as an example structure is used to generate the train and test data. Total number of damage scenarios considered is 829. From the results of application, it is shown that the proposed method can accurately estimate the location and level of damages.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.5
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• pp.91-100
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• 2018

The new seismic retrofit system in study propose is the Dual system, which aims to be applied to the seismically vulnerable low-story buildings. The Dual system is composed of existing structure, external retrofit frame and hysteretic steel dampers installed between former two components. The Dual system dissipates the energy by plastic deformation of steel damper caused by relative displacement due to the differences in stiffness, weight, and eigenperiod of each components. The dynamic test with shaking table was performed to verify the seismic performance of the proposed Dual system. As a result of the dynamic test, it is expected that the Dual system will improve the seismic performance due to the reduction of strain of 56% and the damage reduction of 93%, even though the energy is 1.84 times higher than that of the dual system. And the results of the study are presented as basic data of the study for setting the design range of the dual system.

• Journal of the Korea institute for structural maintenance and inspection
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• v.7 no.3
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• pp.183-191
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• 2003

A four-story reinforced concrete moment resisting frame damaged from an ultimate limit state earthquake is upgraded with prestressing cable bracing. The purpose of this study is to investigate the bracing configuration effects on the 3-D building response using thee different locations of the bracing systems for the retrofitted building. Since the previous work done by the author proved that static incremental loads to collapse analysis as a substitute to dynamic non-linear time history analysis was a valid alternative tool. Thus, static load to collapse analysis is solely applied to evaluate the seismic performance parameters of both the original and upgraded buildings in this study. In results, the exterior bracing system is effective in restraining torsional behavior of the structure under seismic loads, and no sudden failure occurs in this system that enhances the ductility of the building due to the gradual change of building stiffness as the lateral load increases.