• Advances in Computational Design
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• v.6 no.1
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• pp.1-13
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• 2021

Failure of a Multi-storeyed reinforced concrete framed structure occurs when a primary vertical structural component is isolated or made fragile, due to artificial or natural hazards. Load carried by vertical component (column) is transferred to neighbouring columns in the structure, if the neighbouring column is incompetent of holding the extra load, this leads to the progressive failure of neighbouring members and finally to the failure of partial or whole structure. The collapsing system frequently seeks alternative load path in order to stay alive. One of the imperative features of collapse is that the final damage is not relative to the initial damage. In this paper, the effect on the column and beam adjacent to statically removed vertical element in terms of axial force, shear force and bending moment is investigated. Using Alternate load path method, numerical modelling of two dimensional one bay, two bay with variation in storey heights are analysed with FE model in order to obtain better understanding of failure mechanism of multi-storeyed reinforced concrete framed structure. The results indicate that the corner column is more susceptible to progressive collapse when compared to middle column, using this simplified methodology one can easily predict how the structure can be made to stay alive in case of sudden failure of any horizontal or vertical structural element before designing.

• Journal of Korean Society of Steel Construction
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• v.10 no.4 s.37
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• pp.615-627
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• 1998

In order to determine the maximum shear force, the maximum bending moment, the maximum pure torsion. the maximum warping torsion, and the maximum bimoment for the curved girder grid bridges, it is important to find the location of live load applied to the curved girder grid bridges, so that the influence line can be estimated. The fundamental differential equation concerning the behaviour with warping effects for the curved girder is developed by Vlasov. In this paper, the influence line of shear force, bending moment, pure torsion, warping torsion, and bimoment due to unit vertical load and unit torsional moment for curved I-girder grid bridges with variable and constant cross section are obtained by using the finite difference method and compared with respectively.

• Journal of the Korea Concrete Institute
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• v.24 no.5
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• pp.517-524
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• 2012

In this study, the effects of the inelastic shear behavior of beam-column joint and the vertical distribution of lateral load are evaluated considering higher modes on the response of RC OMRF using the pushover analysis. A structure used for the analysis was a 5-story structure located at site class SB and seismic design category C, which was designed in accordance with KBC2009. Bending moment-curvature relationship for beam and column was identified using fiber model. Also, bending moment-rotation relationship for beam-column joint was calculated using simple and unified joint shear behavior model and moment equilibrium relationship for the joint. The results of pushover analysis showed that, although the rigid beam-column joint overestimated the stiffness and strength of the structure, the inelastic shear behavior of beam-column joint could be neglected in the process of structural design since the average response modification factor satisfied the criteria of KBC2009 for RC OMRF independent to inelastic behavior of joint.

• Journal of Korean Society of Steel Construction
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• v.9 no.4 s.33
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• pp.501-513
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• 1997

The general behavior of curved girder including the warping effects is formulated by series of differential equations postulated by Vlasov. In order to determine the maximum shear force, the maximum bending moment, the maximum pure torsion, the maximum warping torsion, and the maximum bimoment for the curved girder grid bridges, it is important to find the location of live load applied to the curved girder grid bridges, so that the influence line can be estimated. In this paper, the influence line of shear force, bending moment, pure torsion, warping torsion, and bimoment due to unit vertical load and unit torsional moment for curved I-girder grid bridges are obtained by using the finite difference method.

• Steel and Composite Structures
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• v.41 no.5
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• pp.637-648
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• 2021

Nowadays, one of the practical, fast and easy ways to strengthen steel elements is the use of Carbon Fiber Reinforced Polymer (CFRP). Most previous research in the CFRP strengthening of steel members has carried out on straight steel members. The main difference between horizontal curved beams and straight beams under vertical load is the presence of torsional moment in the horizontal curved beams. In the other words, the horizontal curved beams are analyzed and designed for simultaneous internal forces included bending moment, torsional moment, and shear force. The horizontal curved steel beams are usually used in buildings, bridges, trusses, and others. This study explored the effect of the CFRP strengthening on the behavior of the horizontal curved square hollow section (SHS) steel beams. Four specimens were analyzed, one non-strengthened curved steel beam as a control column and three horizontal curved steel beams strengthened using CFRP sheets (under concentrated load and uniform distributed load). To analyze the horizontal curved steel beams, three dimensional (3D) modeling and nonlinear static analysis methods using ANSYS software were applied. The results indicated that application of CFRP sheets in some specific locations of the horizontal curved steel beams could increase the ultimate capacity of these beams, significantly. Also, the results indicated when the horizontal curved steel beams were under distributed load, the increase rate in the ultimate capacity was more than in the case when these beams were under concentrated load.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.5
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• pp.399-406
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• 2016

The large scale wind turbine blades usually experience periodic change of inflow speed due to blade rotation inside the ground shear flow region. Because of the vertical wind shear, the inflow velocity in the boundary layer region is maximum at uppermost position and minimum at lowermost position. These spatial distribution of wind speeds can lead to the periodic oscillation of the 6-component loads at hub and low speed shaft of the wind turbine rotor. In this study we compare the aerodynamic loads between two inflow conditions, i.e, uniform flow (no vertical wind shear effect) and normal wind profile. From the computed results all of the relative errors for oscillating amplitudes increased due to the ground shear flow effect. Especially bending moment and thrust at hub, and bending moments at LSS increased enormously. It turns out that the aerodynamic analysis including the ground shear flow effect must be considered for fatigue analysis.

• Journal of the Korean Institute of Navigation
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• v.18 no.2
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• pp.19-40
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• 1994

Several factors can be chosen for evaluating seakeeping performance, such as deck wetness, propeller racing, slamming, rolling, vertical acceleration and vertical bending moment, in consi-deration of the safety of human being, cargo and ship. In fact, there are few developments for an evalua-tion method of seakeepting performance correponding with each ship's characteristics. The purpose of this paper is to develop an quantitative evaluation method of seakeeping performance according to ship types. The scope and the method of this study are as follow. (1) Obtain each response amplitude of ship's motion in waves by Ordinary Strip Method and apply it to short-crested, irregular wave for random process of the factors on seakeeping performance. (2) Define the evaluation index, the dangerousness, the maximum dangerousness and the evaluation diagram. (3) Figure out the different characteristics according to ship types by computer simulation of evaluating seakeeping performance. (4) Adopt vertical acceleration and one of rolling or lateral acceleration as the factors on seakeeping performance by clarifying the correlation of stochastic process. This study developed an evaluation method coincident with each ship's characteristics, and suggested a device for application to actual ship. This method might be useful in developing the practical system of seakeeping performance in accordance with ship types. The ship models for computer simulation are 175m container ship types, 93m tranning ship HANARA as passenger ship type, 259m bulk-carrier type and 164m pure car-carrier type.

• Journal of Industrial Technology
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• v.3
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• pp.103-116
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• 1983

Recent developments in multi-storey buildings for residential purpose have led to the extensive use of shear walls for the basic structural system. When the coupled shear wall system is used, joined together with cast-in-place concrete or mortar (or grout), the function of the continuous joints is a crucial factor in determining the safety of L.P. Precast concrete shear wall structures, because the function of the continuous joints(Vertical wall to wall joints) is to transfer froces from one element(shear wall panel) to another, and if sufficient strength and ductility is not developed in the continuous joints, the available strength in the adjoining elements may not be fully utilized. In this paper, the influence of the stiffness of vertical joints(wet vertical keyed shear joints) on the behaviour of precast shear walls is theoretically investigated. To define how the stiffness of the vertical joints affect the load carrying capacity of L.P.Precast concrete shear wall structure, the L.P.Precast concrete shear wall structure is analyzed, with the stiffness of the vertical joints varying from $K=0.07kg/mm^3$(50MN/m/m) to $K=1.43kg/mm^3$(1000MN/m/m), by using the continuous connection method. The results of the analysis shows that at the low values of the vertical stiffness, i.e. from $K=0.07kg/mm^3$(50MN/m/m) to $K=0.57kg/mm^3$(400MN/m/m), the resisting bending moment and shearing force of precast shear walls, the resisting shearing force of vertical joints and connecting beams are significantly affected. The detailed results of analysis are represented in the following figures and Tables.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.5
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• pp.488-496
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• 2023

Ship and bridge structures are a type of long box-shaped structure, and resistance to vertical bending moment is a key factor in their structural design. In particular, because box girders are repeatedly exposed to irregular wave loads for a long time, the continuous collapse behavior of structural members must be accurately predicted. In this study, plastic collapse behavior, including buckling according to load changes of the box girder receiving pure bending moments, was analyzed using a numerical analysis method. The analysis targets were selected as three box girders used in the Gordo experiment. The cause of the difference was considered by comparing the results of the structural strength experiment with those of non-linear finite element analysis. This study proposed a combination of the entire and local sagging shape to reflect the effect of the initial sagging caused by welding heat that is inevitably used to manufacture carbon steel materials. The procedures reviewed in the study and the contents of the initial sagging configuration can be used as a good guide for analyzing the final strength of similar structures in the future.

• Journal of Dental Rehabilitation and Applied Science
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• v.18 no.4
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• pp.251-276
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• 2002

The purpose of this study was to compare and analyze the stress distribution and displacement of the fully bone anchored bridge and implant-supported overdenture in edentulous mandible on certain conditions such as number of implants, different design of superstructure. Three dimensional analysis was used and nine kinds of models designed for this study. FEM models were created using commercial software[$Rhinoceros^{(R)}$ (Ver. 1.0 Robert McNeel & Associates, USA)], and analyze using commercial software [Cosmos/$Works^{TM}$(Ver. 4.0 Structural Research & Analysis Corp., US A)]. A vertical load and $45^{\circ}$ oblique load of 17kgf were applied at the left 1st. molar. The results were as follows : (1) In the group of OVD, the displacement was reduced as increasing the number of fixture under vertical loading but there was no specific difference in Von Mises stress. Under oblique loading, the displacement was same at the vertical loading but Von Mises stress was reduced in order of OVD-3, OVD-4, OVD-2. But, bending moment reduced according to increasing the number of fixture. (2) In the group of FBAB, under vertical and oblique loading, the magnitude of Von Mises stress and displacement reduced according to increasing the number of fixtures. FBAB-4 and FBAB-5 showed similar score and distribution, but FBAB-6 showed lower value relatively. (3) In cantilever design, the maximum displacement reduced under vertical loading but increased under oblique loading. However, von mises stresses on fixtures increased under vertical and oblique loading. (4) In comparing OVD-group with FBAB-group, FBAB showed low magnitude of displacement in respect of oblique loading. However OVD-group was more stable in respect of stress distribution.