• Elastomers and Composites
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• v.41 no.1
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• pp.40-48
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• 2006

Mechanical systems with rubber parts have been used widely in industry fields. The evaluation of the physical characteristics of rubber is important in rubber application. Rubber material is useful to machine component for excellent shock absorbing characteristics. The impact characteristics of rubber were examined by experimental and finite element method. The impact test was conducted with a free-drop type impact tester. The ABAQUS/Explicit was used for finite element analysis. In the finite element analysis, elastic modulus of rubber using impact force was used as dynamic modulus, which are measured and predicted with dynamic property test and WLF model. The analysis result was coincided with the experimental results.

• Geomechanics and Engineering
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• v.25 no.2
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• pp.99-109
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• 2021

Tunnel provide faster, safer and convenient way of transportation for different objects. The region where it is construction and surrounding medium has significant influence on the overall stability and performance of tunnel. The present simulation has been carried out in order to understand the behaviour of rock tunnel under static loading condition. The present numerical model has been validated with the laboratory scaled model and field data of underground tunnels. Both lined and unlined tunnels have been considered in this paper. Finite element technique has been considered for the simulation of static loading effect on tunnel through Abaqus/Standard. The Mohr-Coulomb material model has been considered to simulate elastoplastic nonlinear behaviour of different rock types, i.e., Basalt, Granite and Quartzite. The four different stages of rock weathering are classified as fresh, slightly, moderately, and highly weathered in case of each rock type. Moreover, extremely weathered stage has been considered in case of Quartzite rock. It has been concluded that weathering of rock and overburden depth has great influence on the tunnel stability. However, by considering a particular weathering stage of rock for each rock type shows varying patterns of deformations in tunnel.

• Steel and Composite Structures
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• v.32 no.5
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• pp.583-594
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• 2019

In recent years, composite concrete-filled steel tubular (CFST) members have been widely utilized in framed building structures like beams, columns, and beam-columns since they have significant advantages such as reducing construction time, improving the seismic performance, and possessing high ductility, strength, and energy absorbing capacity. This paper presents a new composite joint - the composite CFST beam-column joint in which the CFST member is used as the beam. The main components of the proposed composite joint are steel H-beams, CFST beams welded with the steel H-column, and a reinforced concrete slab. The steel H-beams and CFST beams are connected with the concrete slab using shear connectors to ensure composite action between them. The structural performance of the proposed composite joint was evaluated through an experimental investigation. A three-dimensional (3D) finite element (FE) model was developed to simulate this composite joint using the ABAQUS/Explicit software, and the accuracy of the FE model was verified with the relevant experimental results. In addition, a number of parametric studies were made to examine the effects of the steel box beam thickness, concrete compressive strength, steel yield strength, and reinforcement ratio in the concrete slab on the proposed joint performance.

• Structural Monitoring and Maintenance
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• v.6 no.1
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• pp.47-66
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• 2019

One method of retrofitting concrete structures is to use fiber reinforced polymers (FRP). In this research, the shear, torsional and flexural strengthening of self-compacting reinforced concrete (RC) girders are fulfilled with glass fiber reinforced polymer (GFRP) and carbon fiber reinforced polymer (CFRP) materials. At first, for verification, the experimental results were compared with numerical modeling results obtained from ABAQUS software version 6.10. Then the reinforcing sheets were attached to concrete girders in one and two layers. Studying numerical results obtained from ABAQUS software showed that the girders stiffness decreased with the propagations of cracks in them, and then the extra stresses were tolerated by adhesive layers and GFRP and CFRP sheets, which resulted in increasing the bearing capacity of the studied girders. In fact, shear, torsion and bending strengths of the girders increased by reinforcing girders with adding GFRP and CFRP sheets. The samples including two layers of CFRP had the maximum efficiencies that were 90, 76 and 60 percent of improvement in shear, torsion and bending strengths, respectively. It is worth noting that the bearing capacity of concrete girders with adding one layer of CFRP was slightly higher than the ones having two layers of GFRP in all circumstances; therefore, despite the lower initial cost of GFRP, using CFRP can be more economical in some conditions.

• Advances in concrete construction
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• v.7 no.4
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• pp.203-210
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• 2019

Concrete structures in marine environment are susceptible to chloride attack, where chloride diffusion results in the corrosion of steel bar and further lead to the cracking of concrete cover. This process causes structural deterioration and affects the response of concrete structures to different forms of loading. This paper presents the use of ABAQUS Finite Element Software in simulating the processes involved in concrete's structural degradation from chloride diffusion to steel corrosion and concrete cover cracking. Fick's law was used for the chloride diffusion, while the mass loss from steel corrosion was obtained using Faraday's law. Pressure generated by steel corrosion product at the concrete-steel interface was modeled by applying uniform radial displacements, while concrete smeared cracking alongside the Extended Finite Element Method (XFEM) was used for concrete cover cracking simulation. Results show that, chloride concentration decreases with penetration depth, but increases with exposure time at the concrete-steel interface. Cracks initiate and propagate in the concrete cover as pressure caused by the steel corrosion product increases. Furthermore, the crack width increases with the exposure time on the surface of the concrete.

• Structural Engineering and Mechanics
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• v.76 no.5
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• pp.653-661
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• 2020

The paper presents a study regarding rubber compressibility behavior. The objective is to analyze the effect of compression degree of rubber on its mechanical properties and propose a new methodology based on reverse engineering to predict compressibility degree based on uniaxial stretching test and Finite Element Analysis (FEA). In general, rubbers are considered to be almost incompressible and Poisson's ratio is close to 0.5. Since this property is intimately related to the rubber packing density, little changes in Poisson's ratio can lead to significant changes regarding mechanical behavior. The deviatory hyperelastic constants were obtained through experimental data fitting by least squares method for the most relevant constitutive models implemented in commercial software Abaqus, such as: Neo-Hooke, Mooney-Rivlin, Ogden, Yeoh and Arruda-Boyce, whereas the hydrostatic part was determined through an optimization algorithm implemented in the Abaqus environment by Python scripting. The simulation results presented great influence of the Poisson's ratio in the rubber specimen mechanical behavior mainly for high strain levels. A conventional pure volumetric compression test was also carried out in order to compare the results obtained by the proposed methodology.

• Journal of the Korean Society of Safety
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• v.37 no.4
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• pp.101-112
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• 2022

Expanding urbanization practices result in high numbers of buildings being developed in city centers. This high building concentration leads to an increased fire risk, resulting in higher casualty rates and increased economic damages compared to fires in the past. The purpose of this study was to analyze the structural behavior of fire-damaged reinforced concrete buildings using analytical methods and to suggest methods of improving fire resistance in the event of a fire. Damage levels were measured using commercial software to apply the finite element method, ABAQUS, and MIDAS GEN to the dataset. Load-deflection curves were calculated using the effective area and moment of inertia of the fire-damaged columns provided by ABAQUS. The results of this analysis indicate that fire-damaged beams with experience greater deflection from indoor fires than they will from outdoor fires. Fires that occurred on the middle floors were more dangerous than those occurring on higher floors, and eccentrically loaded columns experienced more damage than axially loaded columns. The results indicate that these methods accurately predict structural behaviors of fire damaged concrete columns by considering fire exposure area and eccentric loading.

• Computers and Concrete
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• v.28 no.6
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• pp.585-603
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• 2021

The validation based on the experimental data demonstrates that the concrete strength under triaxial compression (TC) is overestimated by Lubliner-Oller strength criterion (SC) but underestimated by Lubliner-Lee SC in ABAQUS. Moreover, the discontinuous derivatives of failure criterion exists near the unexpected breakpoints. Both resulted from the piecewise linear meridians of the original Lubliner SC with constants γ. Following the screen for the available failure criteria to determine the model parameter γ of Lubliner SC, Menétrey-Willam SC (MWSC) is considered the most promising option with a reasonable aspect ratio Kc but no other strength values required and only two new model parameters introduced. The failure surface of the new Lubliner SC based on MWSC (Lubliner-MWSC) is smooth and has no breakpoints along the hydrostatic pressure (HP) axis. Finally, predicted results of Lubliner-MWSC are compared with other concrete failure criteria and experimental data. It turns out that the Lubliner-MWSC can represent the concrete failure behavior, and MWSC is the optimal choice to improve the applicability of the concrete damaged plasticity model (CDPM) under TC in ABAQUS.

• Advances in Computational Design
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• v.8 no.2
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• pp.97-112
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• 2023

The Finite Element (FE) modeling of Reinforced Concrete (RC) under seismic loading has a sensitive impact in terms of getting good contribution compared to experimental results. Several idealized model types for simulating the nonlinear response have been developed based on the plasticity distribution alone the model. The Continuum Models are the most used category of modeling, to understand the seismic behavior of structural elements in terms of their components, cracking patterns, hysteretic response, and failure mechanisms. However, the material modeling, contact and nonlinear analysis strategy are highly complex due to the joint operation of concrete and steel. This paper presents a numerical simulation of a chosen RC column under monotonic and cyclic loading using the FE Abaqus, to assessthe hysteretic response and failure mechanisms in the RC columns, where the perfect bonding option is used for the contact between concrete and steel. While results of the numerical study under cyclic loading compared to experimental tests might be unsuccessful due to the lack of bond-slip modeling. The monotonic loading shows a good estimation of the envelope response and deformation components. In addition, this work further demonstrates the advantage and efficiency of the damage distributions since the obtained damage distributions fit the expected results.

• Computers and Concrete
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• v.31 no.2
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• pp.163-171
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• 2023

Face gear transmission is widely used in aerospace shunt-confluence transmission system. Tooth wear is one of the main factors affecting its bearing transmission performance. Furthermore, the installation errors of face gear are inevitable. In order to study the wear mechanism of face gear tooth surface with installation errors, based on tooth contact analysis numerical method and Archard wear theory, the UMESHMOTION subroutine in ABAQUS is developed.Combining with Arbitrary Lagrangian-Eulerian adaptive mesh technology, the finite element mesh wear model of abraded face gear pair is established.The preprocessing conditions are set to generate the inp files.Then,the inp files for each corner are imported and batch processed in ABAQUS.The loading tooth contact problem at each rotation angle is solved and the load distribution coefficient among gear tooth, tooth root bending stress, tooth surface contact stress and loaded transmission error are obtained. Results show that the tooth root wear is the most serious and the wear at the pitch cone is close to 0.The wear law of tooth surface along tooth width direction is convex parabola and the wear law along tooth height direction is concave parabola.