• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.10a
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• pp.281-286
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• 1999

This study is object to structural analysis of continuous casting mold. A two-dimensional finite element model was developed to compute the temperature distribution, stress and strain behavior for continuous casting mold. For structural analysis using thermal analysis result from FEM code. In other to structural analysis of continuous casting mold, many variables such as casting speed, cooling condition, film coefficient, convection and load condition are considered.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.6 no.1
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• pp.57-64
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• 2010

PHE(Process Heat Exchanger) is a key component required to transfer heat energy of $950^{\circ}C$ generated in a VHTR(Very High Temperature Reactor) to the chemical reaction that yields a large quantity of hydrogen. Korea Atomic Energy Research Institute established the gas loop for the performance test of components, which are used in the VHTR, and they manufactured a PHE prototype to be tested in the loop. In this study, as part of the high-temperature structural-integrity evaluation of the PHE prototype, which is scheduled to be tested in the gas loop, we carried out high-temperature structural-analysis modeling, thermal analysis, and thermal expansion analysis of the PHE prototype. The results obtained in this study will be used to design the performance test setup for the PHE prototype.

• Structural Engineering and Mechanics
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• v.84 no.6
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• pp.723-731
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• 2022

Functionally graded materials (FGMs) have been spotlighted as an advanced composite material, accordingly the intensive studies have focused on FGMs to examine their mechanical behaviors. Among them is thermal buckling which has been a challenging subject, because its behavior is connected directly to the safety of structural system. In this context, this paper presents the numerical analysis of thermal buckling of metal-ceramic functionally graded (FG) plates. For an accurate and effective buckling analysis, a new numerical method is developed by making use of (1,1,0) hierarchical model and 2-D natural element method (NEM). Based on 3-D elasticity theory, the displacement field is expressed by a product of 1-D assumed thickness monomials and 2-D in-plane functions which are approximated by NEM. The numerical method is compared with the reference solutions through the benchmark test, from which its numerical accuracy has been verified. Using the developed numerical method, the critical buckling temperatures of metal-ceramic FG plates are parametrically investigated with respect to the major design parameters.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.3
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• pp.479-486
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• 2002

In this study, the progressive inelastic deformation, so called, thermal ratchet phenomenon which can occur in high temperature structures of liquid metal reactor was simulated with thermal ratchet structural test facility and 316L stainless steel test cylinder. The thermal ratchet deformation at the reactor baffle cylinder of the liquid metal reactor can occur due to the moving temperature distribution along the axial direction as the sodium free surface moves up and down under the cyclic heat-up and cool-down transients. The ratchet deformation was measured with the laser displacement sensor and LVDTs after cooling the structural specimen which is heated up to 55$0^{\circ}C$ with steep temperature gradients along the axial direction. The temperature distribution of the test cylinder along the axial direction was measured with 28 channels of thermocouples and was used for the ratchet analysis. The thermal ratchet deformation was analyzed with the constitutive equation of nonlinear combined hardening model which was implemented as ABAQUS user subroutine and the analysis results were compared with those of the test. Thermal ratchet load was applied 9 times and the residual displacement after 9 cycles of thermal load was measured to be 1.79mm. The ratcheting deformation shapes obtained by the analysis with the combined hardening model were in reasonable agreement with those of the structural tests.

• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.2
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• pp.91-101
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• 2006

Lately, massive concrete structures are increasingly built. In such massive structures, the heat of hydration of mass concrete causes thermal cracks. To avoid thermal crack, methods widely acceptable for practical use are pre-cooling, pipe cooling and control of placing height. Thermal stress analysis is performed to find the way of controlling the thermal crack of pier footing mat in this paper. The footing mat model for the analysis is $12m{\times}14m$area and 3m height. The analysis results are compared with method of control of lift height and method of pipe cooling. The analysis results show that thermal crack can be removed by method of placing control and pipe cooling at footing mat placed on the ground.

• Design & Manufacturing
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• v.12 no.1
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• pp.41-46
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• 2018

This study proves the causes of cylinder and piston jam by scratches which is the fatal problem of hydraulic breaker through the thermal analysis and thermal-structural coupled field analysis. The trouble from the scratch is a complex problem which can be caused by manufacturing process (this is an internal factor) and the users mistake or contamination in the hydraulic circuit (these are an external factor). Hence, it's not easy to investigate the causes, also hard to prevent the recurrence. In this reason, hydraulic breaker manufacturers are trying to improve the manufacturing process such as machining, heat treatment, grinding, cleaning, also to prevent the contamination in hydraulic circuit and to remove the remains. It's being managed thoroughly by manufacturers. This study shows the effect of the temperature rise by the frictional heat generated when the piston hits the tool on the hydraulic oil while the hydraulic breaker is operating, also the temperature distribution when it starts to affect main components of hydraulic breaker. The stress and the amount of deformation also could be found through thermal-structural coupled field analysis. It proved that the stress and deformation are proportionally increased according to the temperature rise in hit area, and it affects the cylinder and the viscosity of hydraulic oil inside the cylinder when it heats up beyond the certain temperature.

• Journal of Magnetics
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• v.18 no.2
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• pp.125-129
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• 2013

This paper deals with a water-cooled direct drive permanent magnet (DD-PM) motor design for an injection-molding application. In order to meet the requirements for the target application and consider the practical problems of the manufacturing industry, the DD-PM motor is designed in consideration of efficiency and structural strength with many constraints. The performances of the designed motor are estimated not only by magnetic field analysis, but also by thermal and structural analysis. The design and analysis results are presented with experiment results.

• Journal of the Korean Society of Safety
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• v.16 no.4
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• pp.160-167
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• 2001

Cracking in connote structures is one of the main issues of structural design next to ensuring the load-bearing capacity. Thermal analysis is used to prevent thermal mucking, but concrete properties are uncertain variable, and analysis results have uncertainty, too. In this study, sensitivity analysis is performed to investigate the effect of conductivity, specific heal and pouring temperature. The results show that lower conductivity and higher specific heat increase the maximum temperature and maximum tensile stress. The structure with internal restraint is mostly influenced by the change of conductivity and specific heat.

• Proceedings of the Korean Nuclear Society Conference
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• 1999.05a
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• pp.250-250
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• 1999

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.11
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• pp.106-114
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• 2005

This study addresses space simulation test results and thermal modelling verification of HAUSAT-2 nanosatellite STM (Structural-Thermal Model). The thermal modelling of the HAUSAT-2 has been modified in accordance with test results. Thermal analysis results were repeatedly compared with test results for modified thermal modelling. It is verified that the analysis results for modified thermal modelling agree well with test results. Some surface heaters were implemented to simulate solar illumination for HAUSAT-2 Thermal Vacuum/Balance Test. A low-cost and effective thermal test methodology, which is applicable to ultra-small satellite system, was proposed and verified by test results in this study.