• Journal of Institute of Control, Robotics and Systems
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• v.11 no.7
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• pp.615-620
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• 2005

For successful deformable part assembly, information about its deformation as well as possible misalignment between the hole and its respective mating part are essential. Such information can be mainly acquired from visual sensors. In this paper, part deformation and misalignment in deformable cylindrical peg-in-hole tasks are measured by using a visual sensing system. First, a series of experiments to measure the position of an arbitrary point are performed. Next, an algorithm to measure misalignment and part shape as part deformation are presented, and a series of experiments on them are performed. Experimental results show that the proposed algorithms and the system are effective in measuring part deformation and misalignment.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.4
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• pp.33-39
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• 2001

During the turning of the workpiece, cutting heat causes thermal deformation of the cutting tool which influences the surface characteristics of the machined part. This paper presents a study of thermal deformation of the cutting tool. For this purpose, cutting tool is modeled based of Pro/Engineering and the thermal deformation is simulated by means of the finite element method. The thermal effect on the surface roughness profile is simulated by using surface-shaping system. It has been shown that the results of simulation are similar to those of experiment.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.5
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• pp.167-175
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• 1998

A mathematical formulation is presented to model anisotropy from the deformation textures developed in a forming process. In this work, a micro-mechanical-based polycrystalline analysis is implemented into a consistent finite element method for the anisotropic, viscoplastic deformation of polycrystalline metals. As suggested by Taylor, the deformation of each grain in an aggregate is assumed to be same as the macroscopic deformation of an aggregate or a macro-continuum point. Algorithms are developed to represent the plastic anisotropy, such as the anisotropic yield surface and R-value, from the predicted deformation texture. As applications, the evolution of texture in rolling, upsetting and drawing/extrusion processes are simulated and the corresponding changes of mechanical properties such as yield surface and R-value are predicted.

• Steel and Composite Structures
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• v.16 no.5
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• pp.507-519
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• 2014

In this paper, a higher order shear deformation beam theory is developed for static and free vibration analysis of functionally graded beams. The theory account for higher-order variation of transverse shear strain through the depth of the beam and satisfies the zero traction boundary conditions on the surfaces of the beam without using shear correction factors. The material properties of the functionally graded beam are assumed to vary according to power law distribution of the volume fraction of the constituents. Based on the present higher-order shear deformation beam theory, the equations of motion are derived from Hamilton's principle. Navier type solution method was used to obtain frequencies. Different higher order shear deformation theories and classical beam theories were used in the analysis. A static and free vibration frequency is given for different material properties. The accuracy of the present solutions is verified by comparing the obtained results with the existing solutions.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2006.11a
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• pp.213-216
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• 2006

During the last decade several different methods have been proposed for the estimation of thermal deformations in the line heating process. These are mainly based on the assumption of residual strains in the heat-affected zone or simulated relations between heating conditions and residual deformations. However these results were restricted in the application from the too simplified heating conditions or the shortage of the data. The purpose of this paper is to develop a simulator of thermal deformation in the line heating using the artificial neural network. Two neural network predicting the maximum temperature and deformations at the heating line are studied. Deformation data from the line heating experiments are used for learning data for the network. It was observed that thermal deformation predicted by the neural network correlate well with the experimental result.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.10a
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• pp.262-267
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• 2000

During the turning of the workpiece, cutting heat causes thermal deformation of the cutting tool which influences the surface characteristics of the machined part. This paper presents a study of thermal deformation of the cutting tool. For this purpose, cutting tool is modeled based on Pro/Engineering and temperature and deformation are simulated by means of the finite element method. The thermal effect on the surface roughness profile is simulated by using surface-shaping system.

• Structural Engineering and Mechanics
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• v.10 no.5
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• pp.479-489
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• 2000

Based on the stiffness equation of the tapered beam element involving the effects of axial force and shear deformation, numerical investigations are carried out on elastic instability for web-linearly tapered columns with I-section of steel portal frames. Effects of shear deformation on the effective length of the tapered columns with I-section are studied. An efficient approach for determining the effective length of the tapered portal frame columns considering effects of shear deformation is proposed.

• International Journal of Naval Architecture and Ocean Engineering
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• v.11 no.2
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• pp.648-661
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• 2019

Thin fabric-based yacht sails have a cambered shape to generate lift force; however, their shape can be easily deformed by wind pressure and also affected by the deformation of the mast. These deformations can change the airflow characteristics over the sail. Therefore, Fluid-Structure Interaction (FSI) analysis is needed to evaluate the sail force precisely. In this study, airflow over the deformed sail and rig was studied using FSI. Elastic deformation of the sail and rig was obtained by an aerodynamic calculation under dynamic pressure loading on the sail surface. The effects of rig deformation on the aerodynamic performance of the sail were examined according to the rig type and mast flexibilities. As a result, the changes of lift force for a fractional type rig with a thin mast section were more significant than with a masthead rig.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.10 s.241
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• pp.1344-1352
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• 2005

Densification behavior of iron powder under cold stepped plastic deformation was studied. Experimental data were also obtained for iron powder under cold stepped plastic deformation. The elastoplastic constitutive equation based on yield function of Shima and Oyane was implemented into a finite element program (ABAQUS) to simulate compaction responses of i.on powder during cold stepped plastic deformation. Finite element calculations were compared with experimental data for densification, deformed geometry and density distribution. The agreement between finite element results and experimental data was good for iron powder.

• ETRI Journal
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• v.38 no.6
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• pp.1095-1103
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• 2016

We present a method for transferring deformation weights of a human character to three-dimensional (3D) scanned clothes. First, clothing vertices are projected onto a character skin. Their deformation weights are determined from the barycentric coordinates of the projection points. For more complicated parts, such as shoulders and armpits, continuously moving planes are constructed and employed as projection reference planes. Clothing vertices on a plane are projected onto the intersection curve of the plane with a character skin to achieve a smooth weight transfer. The proposed method produces an initial deformation for physically based clothing simulations. We demonstrated the effectiveness of our method through several deformation results for 3D scanned clothes.