• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.9 no.3
• /
• pp.31-38
• /
• 1989

This paper concentrates on the analysis of reinforced concrete(R/C) structures subjected to monotonic loading, from zero to ultimate loads. Tensile cracking, the nonlinear stress-strain relationship for concrete and reinforcement are taken into account the concrete is assumed to be elastic in tension region and elasto-hardening plastic in compression region. The Kupfer's failure criteria and associated flow rule are adopted to govern the plastic behavior of the concrete. The reinforcing bar is considered as a elasto-hardening platic material. The tension stiffening effect of the concrete between cracks is also considered. The numerical error depends on the used finite element mesh size is reduced by correcting the slope of strain softening region of the concrete according to the developed energy criteria.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2000.10b
• /
• pp.1031-1036
• /
• 2000

In this study, a numerical simulation that can effectively predict the strengthening effect of repaired aged RC structures is developed using the axial deformation link elements. In repaired structures, concrete and interface are modeled as quasi-brittle materials. An elastic-perfectly plastic constitutive relationship is introduced for reinforcing bars. Also, a linear-elastic relationship for repair materials such as FRP or CFS. Structural deterioration in terms of corrosion of steel rebar is considered. The interfacial property between steel and concrete which is reduced by corrosion of steel rebar is obtained by comparing numerical results with experimental results of pull out tests. Obtained values are used in repaired reinforced concrete structures under flexural loading conditions. To investigate strengthening effect of the structures repaired with carbon fiber sheet(CFS), repaired and unrepaired RC structures are analyzed numerically. From analysis, rip-off, debonding and rupture failure mechanisms of interface between substrate and CFS can be determined. Finally, strengthening effect according to the variation of interfacial material properties is investigated, and it is shown that interfacial material properties have influence on the mechanical behavior of repaired structure systems Therefore, the developed numerical method using axial deformation link elements can use for determining the strengthening effects and failure mechanism of repaired aged RC structure.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2008.04a
• /
• pp.545-548
• /
• 2008

As the corrosion of reinforcing bar in concrete structures exposed to chloride attack is one of main factors to determine the remaining service life, marine concrete structures have to be designed to protect the chloride penetration. Among the durability design methods such as deterministic method and probabilistic method, design method based on the probabilistic theory has been widely studied. However, the most essential material, data of the material properties related to chloride diffusion, are still insufficient. In this paper, the probabilistic distribution of chloride diffusion coefficients and aging coefficients are derived by the experiment and analysis for the chloride coefficients of concrete containing pozzolans, which are generally used in marine structures.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2006.11a
• /
• pp.17-20
• /
• 2006

It often happen water leakage that roof membrane have a poor condition such as direct exposed to rain, ultraviolet lays, temperature change compare with other part of waterproofing. There are difficult to maintain the quality of waterproofing and durability due to use only few waterproofing materials in practical in spite of development and use the various waterproofing material as solution of these poor condition. Therefore, in this thesis, I would like to know the property to apply field and suggest other method to develop for this waterproofing method to adopt various field condition for roof tops, as searching exposed and complex waterproofing technology for roof tops which is reinforced sheet using rising system have a regular pitch, depth, space.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.11 no.5
• /
• pp.49-59
• /
• 2007

The purpose of this study is to investigate the seismic behavior of reinforced concrete bridge columns using shaking table tests. A computer program, named RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology), for the analysis of reinforced concrete structures was used. Material nonlinearity is taken into account by comprising tensile, compressive and shear models of cracked concrete and a model of reinforcing steel. Solution of the equations of motion is obtained by numerical integration using Hither-Hughes-Taylor (HMT) algorithm. The proposed numerical method for the seismic behavior of reinforced concrete bridge columns using shaking table tests is verified by comparison with reliable experimental results.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.15 no.1
• /
• pp.19-28
• /
• 2011

In this study, nonlinear finite element analysis procedures are presented for the structural performance assessment of damaged reinforced concrete structures. A computer program, named RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology), for the analysis of reinforced concrete structures was used. Material nonlinearity is taken into account by comprising tensile, compressive and shear models of cracked concrete and a model of reinforcing steel. This paper defines a damage index based on the predicted inelastic behavior of reinforced concrete structures. The proposed numerical method for the structural performance of damaged reinforced concrete structures is verified by comparison with reliable experimental results.

• Geotechnical Engineering
• /
• v.13 no.1
• /
• pp.159-168
• /
• 1997

In order to investigate the effect of parameters such as orientation and surface roughness of a reinforcing material as well as the water content of the clay matrix on the stress-strain and failure behavior of reinforced clay, uniaxial compression tests were performed on clay samples reinforced with a steel inclusion Test results showed that the increase or decrease in strength of reinforced clay samples was found to depend on the orientation of a steel inclusion as well as water content of clay samples. The possible weakening mechanism induced by reinforcement in clay samples was related to the development of cracks along the tips of interface between steel inclusion and clay matrix. A theoretical interpretation of failure behavior of reinforced clay was made by using fracture mechanics theory, and the experimental results were compared with the theoretical predictions. The predicted crack propagation direction obtained from fracture criteria for a material containing a closed crack with friction agreed reasonably well with the measured values obtained from tests.

• Journal of the Korea Institute of Building Construction
• /
• v.6 no.4 s.22
• /
• pp.69-75
• /
• 2006

It often happen water leakage that roof membrane have a poor condition such as direct exposed to rain, ultraviolet lays, temperature change compare with other part of waterproofing. There are difficult to maintain the quality of waterproofing and durability due to use only few waterproofing materials in practical in spite of development and use the various waterproofing material as solution of these poor condition. Therefore, in this thesis, I would like to know the property to apply field and suggest other method to develop for this waterproofing method to adopt various field condition for roof tops, as searching exposed and complex waterproofing technology for roof tops which is reinforced sheet using rising system have a regular pitch, depth, space.

• Journal of the Korea Society for Simulation
• /
• v.24 no.3
• /
• pp.69-75
• /
• 2015

This research focuses on structural stability of the multi-aerial platform. In this study, we conduct structural analysis for the lower structures such as sub frame, out-trigger and chassis frame, by using a universal structural analysis program NASTRAN based on 3D CAD data, material properties, load conditions and boundary conditions. We confirm the position of local stress exceeding the yield strength, through structural analysis of 4 cases for load conditions. As the results, it is possible to relax stress concentration in a way such as changing the thickness, reinforcing the material of the lower frames.

• Advances in concrete construction
• /
• v.1 no.1
• /
• pp.1-27
• /
• 2013

Discrete steel fibres can increase significantly the bending and the shear resistance of concrete structural elements when Steel Fibre Reinforced Concrete (SFRC) is designed in such a way that fibre reinforcing mechanisms are optimized. To assess the fibre reinforcement effectiveness in shallow structural elements failing in bending and in shear, experimental and numerical research were performed. Uniaxial compression and bending tests were executed to derive the constitutive laws of the developed SFRC. Using a cross-section layered model and the material constitutive laws, the deformational behaviour of structural elements failing in bending was predicted from the moment-curvature relationship of the representative cross sections. To evaluate the influence of the percentage of fibres on the shear resistance of shallow structures, three point bending tests with shallow beams were performed. The applicability of the formulation proposed by RILEM TC 162-TDF for the prediction of the shear resistance of SFRC elements was evaluated. Inverse analysis was adopted to determine indirectly the values of the fracture mode I parameters of the developed SFRC. With these values, and using a softening diagram for modelling the crack shear softening behaviour, the response of the SFRC beams failing in shear was predicted.