• Journal of the Computational Structural Engineering Institute of Korea
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• v.12 no.4
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• pp.525-535
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• 1999

In this study, a new method of fabricated concrete deck bridge construction is proposed. This paper details the method in which concrete multi-girders and fabricated concrete decks are rested on the upper flange of the girder and the female to female type sheat-key is formed to connect girder and deck. The finite element analysis is performed to verify the accuracy of the structural behaviors of the fabricated concrete deck bridge by comparing with experimental results. The first task performed is the analysis of the equilibrium of the member force occurring between the deck and the girder. After verifying equilibrium of the member force determined by the finite element analysis, this process is applied to the analysis of maximum member force as the position of design load. This task is utilized to determine the safety of each member according to the same scale finite element model. The final process in this study is to compare the deflection of girders used in experiment with that of the same scale finite element model to verify the strength of fabricated cincrete deck bridge. By this comparison, it is shown that the behavior of the fabricated concrete deck bridge is almost same as the finite element analysis. The second task is to analyze the load distribution effect according to the number of diaphragms and the composite effect due to the cinnection of the deck and girder by the finite element analysis. From the results of second task, it is found that the load distribution effect is not related to the number of diaphragms in case of the central loading, but is related to the number of diaphragms for eccentric loading. Analysis of the load distribution indicates that the effective number of diaphragm is three. It is also shown that the maximum deflection is decreased to almost one half due to the composite action of the deck and girder.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.2
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• pp.131-138
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• 2015

In this paper, the modified live-load and designed formula are studied according to the fact the highway bridge design specifications are recently revised. The two examples for composite steel plates and PSC girder bridges are studied. The envelope is analyzed with the finite element models and lateral load distribution method applying the existing highway bridge specification(2010), the newly revised highway bridge specification(2015) and AASHTO LRFD. In case of composite steel plates, length changes between spans are studied, and in case of PSC girder. changes of the number of cross-beams and spans, and span-lengths, are analyzed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.3
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• pp.91-105
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• 1992

For the analysis of multistory frames with sidesway, no adequate procedures can be found in the classical methods of structural analysis. Even well-known procedures such as the slope-deflection method and the moment distribution method may not be effective tools since those methods require a multiple of computational labor and/or yield results of approximate values. In this study, a direct method is developed and proposed for the analysis of multistory frames with sidesway, which is due to the lateral loads, asymmetry of the structure itself, or asymmetry of vertical loadings. The proposed method is to obtain simple forms of equations derived by a mathematical formulation of the moment distribution procedure combined with successive correction concept. Numerical illustrations show that the results obtained by the proposed method agree well with those by rigorous ones. Undoubtedly, this newly developed method can be applied more easily for the analysis of structural frames without joint translation as well as continuous beams.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.315-319
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• 2000

This study is to analyze the effect of the cross beam in bridge design. The analysis on the cross beam using FEM method is to find the best location and numbers of the cross beam in bridges. These analysis will allow economical design and construction in the field.

• International Journal of Highway Engineering
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• v.10 no.4
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• pp.257-267
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• 2008

This study was conducted to investigate the stress distribution in the prestressed concrete pavement (PSCP) when the transverse post tensioning was applied. By performing the structural analyses using a finite element model of PSCP, the effect of anchor spacing and the relationship between the longitudinal and transverse post tensioning were evaluated. The analysis results showed that as the anchor spacing became smaller, the stresses were more uniformly distributed and the ranges of the stress losses were reduced; however, the economy should be considered. As the anchor spacing became larger, the difference between the average transverse stress and the transverse stresses at various locations such as shoulder, wheel pass, and center of the slab, increased. The transverse post tensioning induced the additional tensile forces in the longitudinal tendons, but the magnitude was negligibly small, and the longitudinal and transverse post tensioning could be designed independently. The use of the transverse stress distribution for the design of the post tensioning was also discussed in this paper.

• Journal of the Korea institute for structural maintenance and inspection
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• v.9 no.3
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• pp.151-160
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• 2005

Current bridge design codes do not clearly specify the girder distribution factors for continuous bridges. The objective of the paper is to validate the use of code-specified girder distribution factors for the continuous steel girder bridges, and to provide a basis for recommended girder distribution factors (GDF) for interior girders, suitable for evaluation of existing continuous steel girder bridges. This paper presents the procedure and results of 3-dimensional finite element analysis that were performed on five of continuous steel girder bridges to verify girder distribution factors. The analysis results showed that the live load moment distribution at the negative moment region is very similar to those at the positive moment region in continuous steel girder bridges. It was also found that the GDF's based on the strain values are similar to those based on the deflection. GDF's based on the deflection show marginally better distribution. The analysis results confirmed that the code specified GDF's for continuous steel girder birdges are very conservative.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.3
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• pp.60-68
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• 2017

Since the bridge is the main facility of the road that is the core of the civil infrastructure, the bridge is constructed to ensure stability and serviceability during the traffic use. In order to secure the safety of bridges, evaluating the integrity of bridges at present is an important task in the maintenance work of bridges. In general, to evaluate the load carrying capacity of bridges, it is possible to confirm the superimposed behavior and symmetric behavior of bridges by estimating the lateral load distribution factor of the bridges through vehicle loading tests. However, in order to measure the lateral load distribution factor of a commonly used bridge, a static loading test is performed. There is a difficulty in traffic control. Therefore, in this study, the static displacement component of the bridge measured in the dynamic loading test and the ambient vibration test was extracted by using empirical mode decomposition technique. The lateral load distribution was estimated using the extracted static displacement component and compared with the lateral load distribution factor measured in the static loading test.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.1
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• pp.103-111
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• 2016

This paper presents an adaptive variable weights tuning system for an integrated chassis control with electronic stability control (ESC) and active front steering (AFS) for lateral stability enhancement. After calculating the control yaw moment needed to stabilize a vehicle with a controller design method, it is distributed into the tire forces generated by ESC and AFS using weighted pseudo-inverse-based control allocation (WPCA). On a low friction road, lateral stability can deteriorate due to high vehicle speed. To cope with the problem, adaptive tuning rules on variable weights of the WPCA are proposed. To check the effectiveness of the proposed method, a simulation was performed on the vehicle simulation package, CarSim.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.4
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• pp.1523-1531
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• 2011

Multi-axle driving vehicle are favored for military use in off road operations because of their high mobility on extreme terrains and obstacles. Especially, Military Vehicle needs an ability to driving on hills of 60% angle slope. This paper presents the improvement of the ability of hill climbing for 6WD/6WS vehicle through the optimal tire force distribution method. From the driver's commands, the desired longitudinal force, the desired lateral force, and the desired yaw moment were obtained for the hill climbing of vehicle using optimal tire force distribution method. These three values were distributed to each wheel as the torque based on optimal tire force distribution method using friction circle and cost function. To verify the performance of the proposed algorithm, the simulation is executed using TruckSim software. Two vehicles, the one the proposed algorithm is implemented and the another the tire's forces are equivalently distributed, are compared. At the hill slop, the ability to driving on hills is improved by using the optimum tire force distribution method.

• Magazine of the Korea Concrete Institute
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• v.11 no.2
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• pp.187-196
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• 1999

An experimental investigation was conducted to study the structural behavior of concrete columns confined with welded grids. The full-scale columns with different volumetric ratio, spacing and arrangement of welded reinforcement grids were tested under simulated seismic loading. The columns were subjected to constant axial compression of approximately 20% or 40% of their capacities accompanied by incrementally increasing lateral deformation reversals. The results indicate that the welded reinforcement grid can be used effectively as confinement reinforcement provided that the steel used, have sufficient ductility and the welding process employed does not alter the strength and elongation characteristics of steel. The grids improved the structural performance of columns, which developed lateral drift ratios in excess of 3% with the spacing and volumetric ratio of transverse reinforcement similar to those required by the ACI 318-95 Building Code. Drift capacity further increased when grids with larger number of cells were used. Furthermore, the use of grids reduced congesting of reinforcement while the dimensional accuracy provided perfect support to longitudinal reinforcement.