• Journal of the Korean GEO-environmental Society
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• v.18 no.2
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• pp.53-58
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• 2017

In this paper, we propose a new method to debond between mixed finite elements for porous media in ABAQUS (2014). ABAQUS just provides debonding algorithm for the u-p model using cohesive elements in standard version. However, this approach has a drawback that it is hard to simulate complex debonding problems like element separation, rigid body motion, and contact between separated elements in standard version. ABAQUS-explicit can resolve these complex problems, but cohesive elements for the u-p model cannot be applied. We introduce a new algorithm for debonding for porous media instead of using cohesive elements. In this method, subroutines VUMAT to apply constitutive models and VDISP to separate elements in ABAQUS are used to simulate debonding problems. In addition, a simple 2-D example is demonstrated in the ABAQUS-explicit solver.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1997.04a
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• pp.133-143
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• 1997

In this paper, some of the critical factors in Necking-In process are investigated using a numerical analysis. The optimal processing parameters are established and applied to the actual processes. FEM analysis is carried out based on elastic-plastic work hardening model using ABAQUS/Standard. The results obtained from the commercially available code ABAQUS/Standard are compared with the experimental data and shows a good agreement with experimental data. The purpose of this paper is to search for the relations among the roller angle, feed length, and working force. Stress, strain distribution, displacement and increase in the length of the workpiece are also investigated.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.910-920
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• 1997

In this paper, some of the critical factors in Necking-In process are investigated using a numerical analysis. The optimal processing parameters are established and applied to the actual processes. FEM analysis is carried out based on elastic-plastic work hardening model using ABAQUS / Standard. The results obtained form the commercially available code ABAQUS / standard are compared with the experimental data and shows a good agreement with experimental data. The purpose of this paper is to search for the relations among the roller angel, feed length, and working force. Stress, strain distribution, displacement and increase in the length of the workpiece are also investigated.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.23 no.6
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• pp.635-640
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• 2010

When using finite element pogram ABAQUS to compute material characteristics, one builds a user material subroutine if unique constitutive feature needs to be included. In ABAQUS/Standard, UMAT subroutine should be built, and in ABAQUS/Explicit, VUMAT should be used. Although two subroutines carry out the same type of task, two different programs should be made depending on the working environment, and it is not easy to program the subroutines following the manual without enough understanding of solid mechanics. In this paper, difference between UMAT and VUMAT subroutines is epitomized, and a conversion scheme from UMAT to VUMAT is discussed. An example shows that the two programs give the same stress computation result.

• Transactions of Materials Processing
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• v.10 no.7
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• pp.525-533
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• 2001

PET bottles are main]y manufactured by the stretch blow-molding process. In order to improve the thickness distribution to avoid crack generation at bottom region of one-piece PET bottle, process analysis of stretch blow-molding using a finite element method has been carried out. Finite element analysis has been carried out using ABAQUS/Standard. CREEP user subroutine provided in ABAQUS has been used to model PET behavior that is rate sensitive. Among the process parameters, the effect of plunger movement to thickness distribution of bottle has been considered by axisymmetric analysis. A modified process of plunger movement, which yields more uniform thickness distribution, has been proposed. 3D FE analysis has been done to confirm the validity of the proposed process.

• Structural Engineering and Mechanics
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• v.37 no.5
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• pp.509-527
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• 2011

The paper investigates the dynamic buckling behaviour of a laminated composite stiffened cylindrical shell using the commercial finite element code ABAQUS. The numerical model of the composite shell is validated by static tests. In particular, the experimental collapse test is numerically simulated by a quasi static analysis carried out by both ABAQUS/Standard and ABAQUS/Explicit. The behaviour in the post-buckling field and the collapse load obtained by the analyses are close to the experimental data. The validated model is then used to study the dynamic buckling behaviour with ABAQUS/Explicit. The effects of the loading magnitude and of the loading duration are investigated, implementing in the analysis also first-ply failure criteria. It is observed that the dynamic buckling load is highly affected by the loading duration.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.2
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• pp.58-64
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• 2005

An infinite element for impact problem has been developed using ABAQUS/Standard UEL. 4-node plane strain element was considered, and the constitutive equation was derived from properties of propagation plane body waves. The element acts as unbounded domain to the plane waves generated by impact. The numerical method was tested for the simulation of plate impact. The results show the effectiveness of the infinite element.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.2
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• pp.11-17
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• 2018

Concrete is the well-used material in many architectural and civil structures. The behavior of concrete does exhibit a different characteristic in compression and tension, and it also shows an inelastic-nonlinear behavior. In addition, the concrete properties vary slightly depending on the environmental factor and manufacturer. These properties of concrete make the modeling or simulation of concrete material difficult. In reinforced concrete, particularly, there is a difficulty in bond-slip relationship between concrete and steel. However, in this paper, reserving remainder of these limits the finite element analysis for reinforced concrete beams through ABAQUS simulation has been carried out with some assumptions. Assumptions include the perfect bond of steel and concrete as well as the concrete damaged plasticity (CDP) in concrete property. There is a reasonable agreement between the experimental and numerical results, although the analytical strength and external rod deformation are slightly overestimated. The average and standard deviation between two results are 1.05 and 0.05, respectively. And the models and the computations lead to the evolution of fracture in bending beam.

• Structural Engineering and Mechanics
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• v.64 no.1
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• pp.59-69
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• 2017

The field of fracture mechanics has gained significance because of its ability to address the behaviour of cracks. Predicting the fracture properties of concrete based on experimental investigations is a challenge considering the quasi-brittle nature of concrete. So, there is a need for developing a standard numerical tool which predicts the fracture energy of concrete which is at par with experimental results. The present study is an attempt to evaluate the fracture energy and characteristic length for different grades of concrete using Concrete Damage Plasticity (CDP) model. Indian Standard and EUROCODE are used for the basic input parameters of concrete. Numerical evaluation is done using Finite Element Analysis Software ABAQUS/CAE. Hsu & Hsu and Saenz stress-strain models are adopted for the current study. Mesh sensitivity analysis is also carried to study the influence of type and size of elements on the overall accuracy of the solution. Different input parameters like dilatation angle, eccentricity are varied and their effect on fracture properties is addressed. The results indicated that the fracture properties of concrete for various grades can be accurately predicted without laboratory tests using CDP model.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.287-290
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• 2005

The shearing and punching processes are analyzed with the finite element method using an isotropic material model. The experimental result in the punching process shows that final radiuses of sheet metal according to the rolling direction and transverse direction are different because of the material anisotropy. The material anisotropy is induced by complicated large deformation in the polycrystalline aggregate. The contact region between the punch and sheet metal experiences severe deformation such as shear, compression and tension in the punching process. In this paper, the analysis of punching process for Al 1100 is performed with the ABAQUS Standard. The analysis of texture development and evolution is carried out based on the deformation history in the punching process. The deformation histories are extracted by UMAT in the ABAQUS Standard. The torture development is investigated with the pole figure and yield surface during the punching process.