• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2003.10a
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• pp.127-132
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• 2003

In a today industry, the welding is doing a many portion in structure manufacture. This study is simulated heat of heat-effected zone and researched a mechanical properties and ultrasonic characteristic in used the SS400 and the STS304. As the result mechanical properties of steel that become drawing decreased because of remaining stress by strain gardening according as simulated heat temperature rises, but according as temperature rises in material that do simulated heat after have done annealing, mechanical propensity was improved. The velocity and attenuation become different by effect of remaining stress than effect of material internal microstructure in ultrasonic wave test. In the case of STS304, there was change in mechanical properties by effect that is by strain hardening, but there was no change in material that simulated heat after annealing. When become drawing in ultrasonic waves test, according as simulated heat temperatures rise, change of attenuation coefficient is looked, but material that simulated heat after annealing was no change almost both the volocity and attenuation.

• Journal of Energy Engineering
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• v.13 no.4
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• pp.259-266
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• 2004

Specific heat mechanism of oxide fuel is contributed by lattice vibration, dilatation, conduction electron and defect and excess specific heat. Model of oxide fuel for specific heat consists of specific heat at constant pressure term, dilatation specific heat term and defect specific heat term. In this study experimental and published data on the specific heats of oxide nuclear fuels have been reviewed and analyzed to recommend the best fitting model. The oxide fuels considered in this paper were UO$_2$, mixed (U, Pu) oxides and spent fuel. The specific heat data of spent fuel has been replaced by that of simulated fuel.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.6
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• pp.1-8
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• 2018

The object of this paper is to find the characteristics of fire proof materials through an analytical method and to suggest a proper approach for fire-proof design of reinforced concrete beam strengthened with fiber reinforced polymer (FRP). Heating tests for fire-proof materials were conducted and the thermal conductivities and specific heats of them were simulated through finite element analyses. In addition, a finite element analysis on the beam specimen strengthened with FRP under high temperature, which was conducted by previous researchers, was performed and the analytical result was compared with test result. And then the compatibility of the analytical approach was evaluated. Finally, the heat resistance characteristic of RC beam strengthened with FRP was analyzed by the proposed analytical method and the strength decrease of the beam due to the high temperature was evaluated. From the comparison with analytical and test result, it was found that the heat transfer from outside to inside through the fire-proof materials can be suitably simulated by using the proposed analytical approach.