• Computers and Concrete
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• v.6 no.6
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• pp.505-521
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• 2009

The analysis of prismatic members made of reinforced concrete under inclined bending, especially the computation of ultimate loads, is a pronounced non-linear problem which is frequently solved by discretizing the stress distribution in the cross-section using interpolation functions. In the approach described in the present contribution the exact analytical stress distribution is used instead. The obtained expressions are integrated by means of a symbolic manipulation package and automatically converted to optimized Fortran code. The direct problem-computation of ultimate internal forces given the position of the neutral axis-is first described. Subsequently, two kinds of inverse problem are treated: the computation of rupture envelops and the dimensioning of reinforcement, given design internal forces. An iterative Newton-Raphson procedure is used. Examples are presented.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.579-582
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• 2005

Tunnel lining is the final support of a tunnel and reflects the results of the interaction between ground and support system. Recently it is very difficult to support and manage the tunnel because the cracks on tunnel lining cause problems in supporting and managing tunnels. Therefore the analysis of the cracks is quite strongly required. The major role played by the steel fiber occurs in the post-cracking zone, in which the fibers bridge across the cracked matrix. Because of its improved ability to bridging cracks, steel fiber reinforcement concrete(SFRC) has better crack properties than that of reinforced concrete. In this study, mechanical behaviour of a tunnel lining was examined by model tests. The model tests were carried out under various conditions taking different loading shapes, thicknesses and leakage of lining, and volume content of steel fiber. From these model test, the cracking load, the failure load, defection and cracking position and type were examined and the characteristics of deformation and failure for tunnel lining were estimated and researched.

• Journal of the Korean GEO-environmental Society
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• v.7 no.5
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• pp.67-77
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• 2006

Bearing capacity of soil can be improved by several conventional ground improvement techniques like stabilization and compaction. Recently, the necessity on the reseaches for the bearing capacity of footing reinforced by Geotextile is being significantly increased. In this paper, a series of model tests on sandy ground reinforced by a layer of Geotextile were performed under plane strain condition, and the effects of bearing capacity improvement and behaviour of sandy ground were observed through tests for position and horizontal length, material strength of reinforcement.

• Proceedings of the Korea Concrete Institute Conference
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• 1993.10a
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• pp.226-231
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• 1993

This research is undertaken to the flexural strength, failure mode and ductile capacity of one way concrete slabs, with without splices, reinforcement with Wire-Fabric. Test results are as fallows : (1) Crack of the simple slabs is occured at a position of transerve wire and sntirely crack interval of the fixed slabs is taken place about 20cm, (2)Maximum load of slab with splices has showed almost similar to that of slab without splices, but ductile capacity increased according to rising of splices, (3) Ductile capacity of slab with Deformed Bar is higher 1.44 times than that of slab with Wire-Fabric, and it is higher 3.74 times than that of slab with Loop-wire fabric, but that of specimens of using Wire-Fabric is average 4.6.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.1
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• pp.101-107
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• 2005

The objective of this study is structural analysis and optimum shape of rope brake. The finite element model was implemented to compute the stress, strain and friction force for rope brake. The ANSYS code was used for this analysis. Structural analysis are effected by position and height of reinforcement figure. The structural safety was examined by an establishment angle of the rope brakes which made apply to housing of the most suitable shape. The optimum shape of the rope brake was decided after stress and strain results were compared and examined.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.663-668
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• 2003

In this paper, an environmental factor and a durability resistance factor which adapts the concept of the Load Resistance Factor Design for safety design of RC structures is derived and a basic principle of a durability evaluation for RC structures using the factors is proposed. It is shown that durability of RC structures can be evaluated by comparing predicted value of chloride ion concentration with limit value of concentration for steel corrosion generation in reinforcement steel position and the durability of concrete manufactured for the RC structures can be also evaluated by comparing characteristic diffusion coefficient of concrete with predicted diffusion coefficient during mixture design.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.04b
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• pp.262-266
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• 1995

This paper presents a new adaptive-neuro control scheme to control the velocity and position of SCARA robot with parameter uncertainties. The adaptive control of linear system found wiedly in many areas of control application. While techniques for the adaptive control of linear systems have been well-established in the literature, there are a few corresponding techniques for nonlinear systems. In this paper an attempt is made to present a newcontrol scheme for theadaptive control of ponlinear robot based on a feedforward neural network. The proposed approach incorporates a neuro controller used within a reinforcement learning framework, which reduces the problem to one of learning a stochastic approximation of an unknown average error surface Emphasis is focused on the fact that the adaptive-neuro controoler dose not need any input/output information about the controlled system. The simulation result illustrates the effectiveness of the proposed adaptive-neuro control scheme.

• Proceedings of the KSR Conference
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• 2000.05a
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• pp.431-438
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• 2000

In recent years. the destructive force acting on the ballasted track is on the increase with the speed-up of trains and the number of trains, requiring more labor and expenditure to maintain the track in goof condition. Slab track has been developed to decrease the track maintenance work on earthworks. One type of slab track Rheda has Prefabricated track grid, consisting of rails. Prestressed concrete sleepers and reinforcement rods are aligned into position. and then concrete is then placed to integrate the sleepers into a reinforced concrete track slab. In this paper, a new analysis model for the system analysis of the slab track is presented. Then the analysis results are compared with requirements for slab track.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.933-936
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• 2006

Many non-destructive inspection methods have recently been developed for concrete structures. However, these methods can obtain only physical information of concrete, such as crack depth, delamination or position of reinforcement etc. near its surface. If chemical information is required, sampling and componential analyses may be earned out. Non-destructive method that can detect deterioration factors such as carbonation, chloride content or sulfate attack would be an outstanding innovation in inspection methodologies. In this research, near-infrared spectroscopy and X-ray fluorescence analysis were applied for componential analysis for concrete. These methods are very effective compared to traditional methods, therefore, working efficiency and maintenance cost will be improved.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1998.06a
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• pp.95-101
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• 1998

The steel door inner was manufactured via a new route, tailored blanking process, to remove hinge reinforcement parts, using thicker panels laser welded, instead. It is very important, first of all, in this process, to design optimum configuration of tailored blanks and determine the optimum process control for the stamping. Generally, it was found that the severe deformation reduction behavior during stamping in the thinner panel around weld line caused cracks and the other troubles in formability. It is our purpose of this investigation to introduce how the process control parameters, such as tailored blank configuration, size, location in the die, the position of weld line, BHF, bead configuration, work on the formability. In addition, causes of cracks and movement of weld line after forming were analyzed and compared with computer simulation work.