• Architectural research
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• v.26 no.2
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• pp.31-39
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• 2024

The numerical study focuses on the analysis of the structural behavior of concrete beams containing outdated concrete and offers an innovative method of strengthening them using carbon-fiber-reinforced polymer sheets (CFRP). The focus is on modeling and analyzing the performance of aged concrete beams strengthened by CFRP in the flexural direction. This study presents an ultimate load model for CFRP-strengthened RC beams featuring outdated concrete layers. Validation through four-point bending tests and finite element modeling demonstrated the efficacy of the model. Findings indicate that CFRP sheets significantly enhance beam strength, particularly in structures with outdated concrete layers, resulting in increased ultimate load capacity. Moreover, an inverse relationship between ultimate load and concrete layer height was observed, with the CFS-21-15-30 sample exhibiting the most substantial reduction. Validation of the model was achieved using finite element analysis con-ducted in Abaqus software.

• Steel and Composite Structures
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• v.50 no.5
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• pp.499-513
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• 2024

This paper describes the experimental and numerical investigations of octagonal Concrete-Filled Double Skinned Steel Tube (CFDST) short columns under the influence of various internal sizes of the circular and square steel tubes, with constant cross-sectional dimensions of the external octagonal steel tube under concentric loading. The non-linear finite element analysis of octagonal CFDST columns was executed using the ABAQUS to forecast and compare the axial compression behavior influenced by the various sizes of internal circular and square steel tubes. The study shows that the axial compressive strength and ductility of octagonal CFDST columns were significantly influenced by various internal dimensions of the circular and square steel tubes with the strengths of constituent materials.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2000.04a
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• pp.26-30
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• 2000

• The magazine of the Korean Society for Advanced Composite Structures
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• v.2 no.4
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• pp.31-37
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• 2011

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.7
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• pp.905-912
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• 2013

Rubber is one of the most commonly used materials in various fields because of its unique viscoelastic properties. Friction occurs when a tire constantly makes contact with the ground. As a result, friction causes wear. The frictional energy caused by friction is a primary factor in the wear mechanism. The frictional energy is affected by various conditions (temperature, roughness of ground, shape of rubber, load, and materials). In this study, the analysis was preceded by considering the vertical load and the horizontal velocity to the rubber using ABAQUS/explicit. The contact pressure, and friction energy are derived using the shear force and slip distance. The actual behavior of the rubber test data were compared with the analysis results.

• Journal of the Korean Geotechnical Society
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• v.18 no.4
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• pp.215-228
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• 2002

In a companion paper. (Oh, 2002), the constitutive model, called GUX model, was implemented as a user subroutine in ABAQUS code, where the GUX model could describe the behavior of overall strain range. An accuracy analysis verified that the implicit stress integration maintained the accuracy of solutions successfully. Since the GUX model is an anistropic hardening elasto-plastic constitutive model based on total stress concept, geotechnical problems under fully drained or undrained condition can be analyzed after acquisition of stress-strain relationships from drained or undrained triaxial tests. This study includes the analyses of the stability of embankments on soft clays and weathered soils and the example of axially loaded soil-pile system. In the large deformation analyses, geometric nonlinearity was considered and the result of analyses with GUX model was compared with that of Mises model for the overall strain range behavior.

• Coupled systems mechanics
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• v.1 no.4
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• pp.381-395
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• 2012

Dynamic response of Pile Supported Structures is highly depended on Soil Pile Structure Interaction. In this paper, by comparison of experimental and numerical dynamic responses of a prototype jacket offshore platform for both hinge based and pile supported boundary conditions, effect of soil-pile-structure interaction on dynamic characteristics of this platform is studied. Jacket and deck of a prototype platform is installed on a hinge-based case first and then platform is installed on eight skirt piles embedded on continuum monolayer sand. Dynamic characteristics of platform in term of natural frequencies, mode shapes and modal damping are compared for both cases. Effects of adding and removing vertical bracing members in top bay of jacket on dynamic characteristics of platform for both boundary conditions are also studied. Numerical simulation of responses for the studied platform is also performed for both mentioned cases using capability of ABAQUS and SACS software. The 3D model using ABAQUS software is created using solid elements for soil and beam elements for jacket, deck and pile members. Mohr-Coulomb failure criterion and pile-soil interface element are used for considering nonlinear pile soil structure interaction. Simplified modeling of soil-pile-structure interaction effect is also studied using SACS software. It is observed that dynamic characteristics of the system changes significantly due to soil-pile-structure interaction. Meanwhile, both of complex and simplified (ABAQUS and SACS, respectively) models can predict this effect accurately for such platforms subjected to dynamic loading in small range of deformation.

• Structural Engineering and Mechanics
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• v.66 no.4
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• pp.505-513
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• 2018

Steam flooding is widely used in heavy oil reservoir with coupling effects among the formation temperature change, fluid flow and solid deformation. The effective stress, porosity and permeability in this process can be affected by the multi-physical coupling of thermal, hydraulic and mechanical processes (THM), resulting in a complex interaction of geomechanical effects and multiphase flow in the porous media. Quantification of the state of deformation and stress in the reservoir is therefore essential for the correct prediction of reservoir efficiency and productivity. This paper presents a coupled fluid flow, thermal and geomechanical model employing a program (MATLAB interface code), which was developed to couple conventional reservoir (ECLIPSE) and geomechanical (ABAQUS) simulators for coupled THM processes in multiphase reservoir modeling. In each simulation cycle, time dependent reservoir pressure and temperature fields obtained from three dimensional compositional reservoir models were transferred into finite element reservoir geomechanical models in ABAQUS as multi-phase flow in deforming reservoirs cannot be performed within ABAQUS and new porosity and permeability are obtained using volumetric strains for the next analysis step. Finally, the proposed approach is illustrated on a complex coupled problem related to steam flooding in an oil reservoir. The reservoir coupled study showed that permeability and porosity increase during the injection scenario and increasing rate around injection wells exceed those of other similar comparable cases. Also, during injection, the uplift occurred very fast just above the injection wells resulting in plastic deformation.

• Proceeding of KASS Symposium
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• 2008.05a
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• pp.119-124
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• 2008

Space structure is a appropriate shape that resists external force only with in-plane force by reducing the influence of bending moment, and it maximizes the effectiveness of structure system. The space structure should be analized by nonlinear analysis regardless static and dynamic analysis because it accompanies large deflection for member. To analyze the structure of the space structure exactly generally geometrically nonlinear and material nonlinear, complex nonlinear analysis are considered. To settle the weakness that geometric nonlinear problem does not consider nonlinear as per trait and position of the structure material and that the nonlinear matter of structure material also does not consider nonlinear as per geometric form. Therefore, In this paper, analysis is considered geometric nonlinear and material nonlinear simultaneous conditioning, and traced load-deflection curve by using ABAQUS which is the general purpose of the finite element program.

• Journal of the Korean Geotechnical Society
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• v.19 no.5
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• pp.233-241
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• 2003

Geotextile tube is hydraulically filled with dredged materials and has been applied to coastal protection and scour protection, dewatering method of slurry, and isolation of contaminated material. Recently, geotextile tube technology is no longer alternative construction technique but suitable desired solution. In this paper, the numerical analysis was performed to investigate the behavior of geotextile tube with various properties of geotextile sheet and hydraulic pumping conditions. Numerical analysis was executed to compare with the results from the large-scale field model tests, and also with those of plane strain analysis and 3-D FEM analysis. A geotextile tube was modeled using the commercial finite element analysis program ABAQUS and the one-quarter of tube was modeled. Behavior of geotextile tube during the hydraulic pumping procedure was analyzed by comparing the large-scale field model test and numerical analysis. The shape variation and maximum tube height between the numerical analysis results and large-scale filed test results are turned out to be in a good agreement.