• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.6 no.3
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• pp.44-51
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• 1997

Unsteady-state temperature distributions and thermal deformations of the spindle of a high precision lathe are studied in this paper. Three dimensional model is built for analysis, and the amount of heat generation of bearing and the thermal characteristic values including heat transfer coefficient are estimated. Temperature distributions and thermal deformations of a model are analyzed using the finite element method and the thermal boundary values. Numerical results are compared with the measured data. The results show that the thermal deformations and the temperature distributions of the dpindle of a high precision lathe can be reasonably estimated using the three dimensional model and the finite element method.

• Journal of the Korean Society for Advanced Composite Structures
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• v.3 no.4
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• pp.17-26
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• 2012

This study presents a governing equations of bending behavior of anisotropic sandwich plates with multi-layered laminated composite faces. Based on zig-zag models for through thickness deformations, the shear deformation of composite faces is included. All edges of plate are assumed to be simply supported. Results of the bending analysis under lateral loads are presented for the influence of various lay up sequences of antisymmetric angle-ply laminated faces. The accuracy of the approach is ascertained by comparing solutions from the sandwich plates theory with composite faces to the laminated plates theory. Since the present analysis considers the bending stiffness of the core and also the transverse shear deformations of the laminated faces, the proposed method showed higher than that calculated according to the general laminated plates theory. The information presented might be useful to design sandwich plates structure with polymer matrix composite faces.

• 기술발표회
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• s.2006
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• pp.35-44
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• 2006

Supporting method of a Temporary retaining wall for underground excavation project are adopted by systems of strut, anchor, nail, raker, etc. Strut system and Raker system of these methods are mostly used preloading jack to minimize deformations of retaining wall. We determinate efficient preloading to analysis these strut-preloadings, deformations of retaining wall, axial forces, and etc.. This study is analysed that preloading applied 0%, 10%, 20%, 30%, ...., 100% for strut and raker installed by CIP temporary retaining wall. This study results that adequate preloadings were determined to analysis correlations of preloading, deformations of wall, maximum bending moment, axial force of strut, and displacement of surrounding.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1637-1646
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• 2008

Deformations of bridge deck ends on abutment can cause extreme deformations on track. Especially, since slab track was fixed onto the bridge deck slab on concrete slab track installed bridges, deformations of bridge deck ends directly affect the slab track behavior, and thus these interactions can bring about the premature failure of rail fastenings or other deteriorations to lower the serviceability. In this study, a foreign standard to evaluate forces on track components caused by the track-bridge interactions and the behavior of bridge deck ends was investigated and for real scale bridges. It was found that rail support spring coefficients, as well as toe loads, support spacing were very important parameters.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.6
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• pp.81-90
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• 1994

Finite element analysis is performed for transient thermal deformation of a shadow mask inside the Braun tube and the landing shift or mislanding of the electronic beam is calclated. The shadow mask has numerous slits through which the electronic beams are guided to land on the designed phosphor. Its thermal deformations therefore cause the mislanding of the electronic beam and result in decolorization of a screen. For realistic finite element analysis, firstly the effective thermal conductivity and the effective elastric modulus are calculated, and the shadow mask is modeled as shell without slits. Next the nonlinear finite element formulation is developed for transient heat transfer on the shadow mask, wherein thermal radiation is a major heat transfer mechanism. Analysis of the resulting thermoelastic deformations is followed, from which the mislanding of the electronic beam is obtained. The present finite element scheme may be efficiently used for thermal deformation design of a shadow mask.

• Smart Structures and Systems
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• v.9 no.4
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• pp.313-333
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• 2012

Reinforced concrete (RC) framed buildings dissipate the seismic energy through yielding of the reinforcing bars. This yielding jeopardizes the serviceability of these buildings as it results in residual lateral deformations. Superelastic Shape Memory Alloys (SMAs) can recover inelastic strains by stress removal. Since SMA is a costly material, this paper defines the required locations of SMA bars in a typical RC frame to optimize its seismic performance in terms of damage scheme and seismic residual deformations. The intensities of five earthquakes causing failure to a typical RC six-storey building are defined and used to evaluate seven SMA design alternatives.

• Journal of the Korea Computer Graphics Society
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• v.10 no.1
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• pp.15-21
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• 2004

This paper proposes a real-time technique for simulating large rotational deformations. Modal analysis based on a linear strain tensor has been shown to be suitable for real-time simulation, but is accurate only for moderately small deformations. In the present work, we identify the rotational component of an infinitesimal deformation, and extend linear modal analysis to track that component. We then develop a procedure to integrate the small rotations occurring al the nodal points. An interesting feature of our formulation is that it can implement both position and orientation constraints in a straightforward manner. These constraints can be used to interactively manipulate the shape of a deformable solid by dragging/twisting a set of nodes, Experiments show that the proposed technique runs in real-time even for a complex model, and that it can simulate large bending and/or twisting deformations with acceptable realism.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.349-352
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• 2004

In this study, a strut-and-tie models for the coupling beam based on deformations are presented. To design shear-dominated R/C coupling beams, it is important to consider shear strength deterioration with required deformations. This study proposes the method of estimating shear strength of the reinforced concrete coupling beams. The proposed method determines the strain states from target displacements based on the nonlinear truss analysis. The estimated horizontal strain of beam is then used in calculating the strength of the diagonal strut with compatibility conditions. The deterioration of shear strength of the coupling beam depends on the strength degradation of struts due to plastic deformations.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.493-496
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• 2004

The change of creep deformation mechanism due to the persistent change of stress conditions requires the constitutive relation for the analysis of long tenn behaviors considering age dependent material properties of concrete. In the present research, the process of time dependent behaviors in structure is divided into two stages; the non-mechanical deforming level which causes creep and shrinkage deformations, and the mechanical deforming level which causes mechanical deformations by the restraints of non-mechanical deformations due to internal or external factors. The incremental constitutive relation is derived by expanding the total stress-strain relation on the present time, with respect to the reference time using the Taylor series, and the modulus of elasticity in early ages of concrete was defined thru this process.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.448-451
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• 2005

It was observed that after unloading or removal of the load from the specimen subjected to bending stress, partial or full elastic spring back occurred and considerable stresses have resulted while plastic deformation was considered. ABAQUS is a suite of powerful engineering simulation programs, based on the finite element method. In this paper, it was used as the main tool to analyze elastic and plastic deformations of hi-material metal joint. In the case of elastic deformations, the results were comparable to the theoretical data. Plastic deformations and residual stresses of hi-material metal joint under bending moment were obtained by ABAQUS; where the theory needs to be studied and improved further to verify the results.