• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.5
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• pp.182-189
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• 2002

This paper is concerned with a collapse behavior analysis for a thin-walled structure considering farming effects. Numerical simulation is carried out with a finite element limit analysis in order to identify forming effects on collapse behavior of a thin-walled structure such as an S-rail. The formed S-rail contains fabrication histories such as residual stress, work hardening, non-uniform thickness distribution and geometric changes resulted from the forming process. The collapse behavior analysis of an S-rail with forming effects leads to different results from that without such effects. The present study deals with the collapse analysis of the S-rail fabricated with the typical forming, trimming and springback processes. Collapse properties such as the collapse load, the collapse mode and the energy absorption are calculated and investigated In order to identify forming effects. It is fully demonstrated that the design of thin-walled structures needs to consider the forming effects for a proper assessment of the load-carrying capacity and the deformation of the formed structures.

• Journal of the Earthquake Engineering Society of Korea
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• v.22 no.6
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• pp.353-360
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• 2018

This paper is to investigate the micro-behavior of the double-span beams with WUF-W seismic connection under combined axial tension and moment and to propose the rational rotational capacity of it for progressive collapse-resistant analysis and design addressing the stress and strain transfer mechanism. To this end, the behavior of the double-span beams under the column missing event is first investigated using the advanced nonlinear finite element analysis. The characteristics of fracture indices of double-span beams with WUF-W connection under combined axial tension and flexural moment are addressed and then proposed the rational rotational capacity as the basic datum for the progressive collapse-resistant design and analysis. The distribution of fracture indices related to stress and strain for the double-span beams is investigated based on a material and geometric nonlinear finite element analysis. Furthermore, the micro-behavior for earthquake and progressive collapse is explicitly different.

• Transactions of the Korean Society of Automotive Engineers
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• v.1 no.2
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• pp.42-48
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• 1993

In this paper, dynamic collapse behavior of the rectangular tube under impact loading is anlayzed using nonlinear finite element method of shell element. In case of shell element formulation using corotational element coordinates system, dynamic collapse behavior is analyzed without initial imperfection, and with initial imperfection. This paper reveals that the collapse of a rectangular tue without initial imperfection is caused by an error of transformation of the corotational coordinates system.

• Steel and Composite Structures
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• v.50 no.3
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• pp.249-263
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• 2024

This article presents a comparative analysis of seismic behavior in steel-beam reinforced concrete column (RCS) frames versus steel and reinforced concrete frames. The study evaluates the seismic response and collapse behavior of RCS frames of varying heights through nonlinear modeling. RCS, steel, and reinforced concrete special moment frames are considered in three height categories: 5, 10, and 20 stories. Two-dimensional frames are extracted from the three-dimensional structures, and nonlinear static analyses are conducted in the OpenSEES software to evaluate seismic response in post-yield regions. Incremental dynamic analysis is then performed on models, and collapse conditions are compared using fragility curves. Research findings indicate that the seismic intensity index in steel frames is 1.35 times greater than in RCS frames and 1.14 times greater than in reinforced concrete frames. As the number of stories increases, RCS frames exhibit more favorable collapse behavior compared to reinforced concrete frames. RCS frames demonstrate stable behavior and maintain capacity at high displacement levels, with uniform drift curves and lower damage levels compared to steel and reinforced concrete frames. Steel frames show superior strength and ductility, particularly in taller structures. RCS frames outperform reinforced concrete frames, displaying improved collapse behavior and higher capacity. Incremental Dynamic Analysis results confirm satisfactory collapse capacity for RCS frames. Steel frames collapse at higher intensity levels but perform better overall. RCS frames have a higher collapse capacity than reinforced concrete frames. Fragility curves show a lower likelihood of collapse for steel structures, while RCS frames perform better with an increase in the number of stories.

• Earthquakes and Structures
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• v.12 no.3
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• pp.297-307
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• 2017

Evaluation on the sidesway seismic collapse capacity of the widely used low- and medium-height structures is meaningful. These structures with such type of collapse are recognized that behave as inelastic deteriorating single-degree-of-freedom (SDOF) systems. To incorporate the deteriorating effects, the hysteretic loop of the nonlinear SDOF structural model is represented by a tri-linear force-displacement relationship. The concept of collapse capacity spectra are adopted, where the incremental dynamic analysis is performed to check the collapse point and a normalized ground motion intensity measure corresponding to the collapse point is used to define the collapse capacity. With a large amount of earthquake ground motions, a systematic parameter study, i.e., the influences of various ground motion parameters (site condition, magnitude, distance to rupture, and near-fault effect) as well as various structural parameters (damping, ductility, degrading stiffness, pinching behavior, accumulated damage, unloading stiffness, and P-delta effect) on the structural collapse capacity has been performed. The analytical formulas for the collapse capacity spectra considering above influences have been presented so as to quickly predict the structural collapse capacities.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.12
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• pp.2011-2018
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• 2003

To analyze the bending collapse behavior of an aluminum square tube beam under a bending load, a finite element simulation for the four-point bending test has been performed. Using an aluminum tube beam specimen partly inserted with two steel bars, the local buckling deformation near the center of the tube beam was induced. The maximum bending load and the bending collapse behavior obtained from the numerical simulation were in good agreement with experimental results. Using a combination of the four-point bending test and its finite element simulation, analysis of the local buckling and the accompanied bending collapse behavior of aluminum tube beam could be quantitative accomplished.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.5
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• pp.1-9
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• 1998

The analysis concerns collapse behavior of framed vehicle models with the change of design parameters at the initial stage of conceptual design. Collapse analysis of a vehicle model with framed structures has been carried out using finite element limit analysis. The analysis makes sequential changes of design parameters from an initial model with frames of uniform section so as to stage then weak parts. As a result of those design changes, the collapse load of a model has been increased and the deflection toward a passenger room has been reduced. The results demonstrate the versatility of finite element limit analysis as a tool that confirms the safety of vehicle models.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.20 no.3
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• pp.239-246
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• 2007

In this paper a new equivalent static analysis method of dynamic behavior during progressive collapse is presented. The proposed analysis method uses the equivalent nodal load for the element stiffness which represents the dynamic behavior influence caused by the deletion of elements during progressive collapse analysis. The proposed analysis method improves the efficiency of progressive collapse analysis haying the iterative characteristic because the inverse of the structural stiffness matrix is roused in the reanalysis. By comparing the results obtained by this analysis method with those of GSA code analysis and time history analysis, it is shown that the results obtained by this analysis method more closely approach to those of time history analysis than by GSA code analysis.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.25 no.1
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• pp.19-26
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• 2012

In this study the progressive collapse behavior of a moment frame with infill steel panels is evaluated using nonlinear static pushdown analysis. The analysis model is a two story two span structure designed only for gravity load, and the load-displacement relationship is obtained with the center column removed. To obtain local stress and strain as well as the global structural behavior, finite element analysis is conducted using ABACUS. Through the analysis the effect of the span length and the thickness of the steel plate on the progressive collapse behavior of the structure is investigated, and the effect of the dividing the infill panel using stud columns is also studied. According to the analysis results, the thickness of the panels required to prevent progressive collapse increases as the span length increases, and as the number of panel division increases the progressive collapse resisting capacity increases slightly but the effect is not significant. It is also observed that when the infill panel is installed in only a part of the span the progressive collapse resisting capacity is somewhat increased.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.10 s.253
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• pp.1269-1275
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• 2006

The purpose of this study is to investigate the effect of bend angle on the collapse behavior of locally wall thinned pipe bends. For this purpose, the present study performed three-dimensional finite element analysis on the 30-, 60-, and 90-degree pipe bends with local wall thinning at the center of intrados, extrados, and crown, and evaluated the collapse moment for different thinning dimensions under closing- and opening-mode bending with a constant internal pressure. The results showed that, for intrados and extrados wall thinning, the reduction in the collapse moment due to local wall thinning became significant with decreasing bend angle of pipe bends. This effect of bend angle was enhanced with increasing thinning dimensions, and it was clearer fur opening-mode bending than for closing-mode bending. For crown wall thinning, however, the effect of bend angle was unclear and was less sensitive to the change of wall thinning shapes.