• 자동차안전학회지
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• 제6권2호
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• pp.5-11
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• 2014

Front side member of the front impacted vehicle plays a key role in minimizing the impacting load transferred to the compartment. To perform that required function, axial collapse should be dominant during side member crashing and, prior to designing side member, it is crucial to minimize bending moment occurred at the front end. In this study, for FE model of a SUV front body, front impact analyses were carried to find out bumper stay design which effectively develope axial collapse in the side member. As a previous work, the thickness of side member reinforcement were changed. Next, the inner thickness of bumper stay was increased. Also, the bead shape and location were modified. Final front body model showed much more axial collapsed mode and enhanced crash performance. In addition, a stay of octagon section was adopted and that model exhibited distinctive increase in impact energy absorption.

• Structural Engineering and Mechanics
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• 제6권4호
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• pp.395-409
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• 1998

This paper concerns the development and implementation of an orthotropic, stress resultant elasto-plastic finite element model for the collapse load analysis of reinforced concrete plates. The model implements yield line plasticity theory for reinforced concrete. The behaviour of the yield functions are studied, and modifications introduced to ensure a robust finite element model of cases involving bending and twisting stress resultants ($M_x$, $M_y$, $M_{xy}$). Onset of plasticity is always governed by the general yield-line-model (YLM), but in some cases a switch to the stress resultant form of the von Mises function is used to ensure the proper evolution of plastic strains. Case studies are presented, involving isotropic and orthotropic plates, to assess the behaviour of the yield line approach. The YLM function is shown to perform extremely well, in predicting both the collapse loads and failure mechanisms.

• Structural Engineering and Mechanics
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• 제36권4호
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• pp.421-445
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• 2010

In this paper the formulation of an efficient frame element applicable for nonlinear analysis of 3D reinforced concrete (RC) frames is outlined. Interaction between axial force and bending moment is considered by using the fibre element approach. Further, section warping, effect of normal and tangential forces on the torsional stiffness of section and second order geometrical nonlinearities are included in the model. The developed computer code is employed for nonlinear static analysis of RC sub-assemblages and a simple approach for extending the formulation to dynamic cases is presented. Dynamic progressive collapse assessment of RC space frames based on the alternate path method is undertaken and dynamic load factor (DLF) is estimated. Further, it is concluded that the torsional behaviour of reinforced concrete elements satisfying minimum standard requirements is not significant for the framed structures studied.

• International Journal of Naval Architecture and Ocean Engineering
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• 제12권1호
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• pp.902-909
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• 2020

It is announced a new procedure for the real-time overall hull response monitoring system depends on inclinometer sensor data. The procedure requires a few inclinometer sensors' data, located on the deck. Sensor data is used to obtain curvature values; and curvature values are used to find out displacements or relevant moment values according to pre-calculated moment-curvature diagrams. Numerical studies are demonstrated with reasonable accuracy for the pre-ultimate and the post-ultimate nonlinear behaviors. Elastic, inelastic, and post-collapse structural bending moment capacity determination of the hull has been presented. The proposed inverse engineering technique will be able to see the response of the hull in real-time with high accuracy to manage the course and speed when cruising or control the loading and the unloading process at the port.

• 한국자동차공학회논문집
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• 제22권2호
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• pp.52-59
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• 2014

Front impacted SUV vehicle shows that the front parts of side members are collapsed by the bending due to the transverse load exerted at the end of side members. Side member models were impacted with various angles in order to study the crash performance according to the impact angle. Even for the small impact angle of $10^{\circ}$, crash performance seriously deteriorated and the deformations for impact angle $15^{\circ}$ were similar to those from the front body impact analysis. In addition, the angled front impact analysis for the straight member with hat section was carried out and the effects of inner reinforcement shape on crash performance was investigated.

• 한국지진공학회논문집
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• 제16권6호
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• pp.13-20
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• 2012

In this study, 5-story structures were designed in accordance with KBC2009 for inelastic time history analysis of RC IMRF. Bending moment-curvature relationship for beam and column was identified with fiber model and bending moment-rotation relationship for beam-column joint was calculated with simple and unified joint shear behavior model and moment equilibrium relationship for the joint. The hysteretic behavior was simulated with three-parameter model suggested in IDARC program. The analytical results showed that the inelastic shear behavior of the joint could be neglected in the structural design for seismic design category C but the structure of category D did not satisfy the criteria of FEMA 356 for collapse prevention performance level.

• Steel and Composite Structures
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• 제6권4호
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• pp.335-351
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• 2006

The present paper hopes to elucidate the problem of determining if a given I-shaped cross-section is properly proportioned to accommodate sufficient plastic hinge rotation capacity to facilitate the redistribution of moments in a structural system as needed to accommodate the formation of a collapse mechanism. It might be tempting to believe that application of the limiting flange plate slenderness value for the case of major axis flexure are applicable in this case; since the pervasive belief is that this approach ought to be conservative. However, the present research study indicates that this is not the case and thus more sophisticated analysis techniques are required to better understand this case.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표논문집(II)
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• pp.438-443
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• 1998

Softening os the name used for decreasing bending moment at advanced flexural deformation. To accommodate softening deformation in analysis, it is assumed that a hinge has finite length. The softening analysis of R/C frames relies on the primary assumption that softening occurs over a finite hinge length and that the moment-curvature relationship for any section may be closely described by a trilinear approximation. A stiffness matrix for elastic element with softening regions are derived and the stiffness matrix allows extension of the capability of an existing computer program for elastic-plastic analysis to the softening situation. The effect of softening on the collapse load of R/C frame is evaluated.

• Journal of Advanced Research in Ocean Engineering
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• 제3권1호
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• pp.1-14
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• 2017

The safety analysis of an earthquake is carried out during the operation of a subsea pipeline and an onshore pipeline. Several cases are proposed for consideration. In the case of a buried pipeline, permanent ground deformation by the earthquake and an increase of internal pressure by the acceleration of the earthquake should be considered. In the case of a subsea pipeline, a bending moment is caused by liquefaction of the backfill material on a trenched seabed, etc., which results in a high bending moment of the buried pipeline. The bending moment causes the collapse of the subsea pipeline or a leak of crude oil or gas, which results in economic loss due to enormous environmental contamination and social economic loss owing to operation functional failure. Thus, in order to prevent economic loss and operation loss, structurally sensitive design with regard to seismic characteristics must be performed in the buried pipeline in advance, and the negative impact on the buried pipeline must be minimized by conducting a thorough analysis on the seabed and backfilling material selection. Moreover, it is proposed to consider the selection of material properties for the buried pipeline. A more economical review is also required for detailed study.

• 대한기계학회논문집A
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• 제25권1호
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• pp.81-88
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• 2001

This study proposed an analytical method to evaluate a local allowable wall thickness (LAWT) for locally thinned pipe subjected to internal pressure and bending moment. In this method, the stresses in the thinned region were calculated by finite element analysis and plastic collapse was applied as a failure criterion of thinned pipe. Using this method, LAWT for a simplified thinned pipe was evaluated with variation in axial extent of thinned area, and it was compared with allowable wall thickness provided by previous pipe wall thickness criteria. The results showed that the LAWT was lower, about 50%, than that calculated by construction code or ASME Code N-597, and it was higher, about 2 times, than that estimated by evaluation model based on pipe experiments. In addition, LAWT was decreased with increasing axial extent of thinned area and saturated with further increase in axial extent. And, the variation in LAWT with axial extent of thinned area depended on type of load, especially a magnitude of bending moment, considering in the evaluation.