• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.11
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• pp.1175-1181
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• 2015

A heat insulating material used in the industrial site normally derives its heat insulating performance by using a low thermal conductivity material such as glass fiber. In case of the metal insulation for nuclear power plant, in contrast, only TP 304 stainless steel foil having high thermal conductivity is the only acceptable material. So, it is required to approach in structural aspect to ensure the insulation performance. In this study, the design factors related to the metal insulation internal structure were determined considering the three modes of heat transfer, i.e., conduction, convection, and radiation. The analysis of heat flow was used to understand the ratio of the heat transfer from each factor to the overall heat transfer from all the factors. Based on this study, in order to minimize the convection phenomenon caused by the internal insulation, a multiple foil was inserted in the insulation. The increase in the conduction heat transfer rate was compared, and the insulation performance under the three modes of heat transfer was analyzed in order to determine the internal geometry.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.1
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• pp.171-178
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• 2019

Fiber-reinforced polymer (FRP) composites have proved to be reliable as strengthening materials. Most of existing studies used single types of FRP composites. Therefore, in this experimental study, carbon FRP sheet, aramid FRP sheet, and hybrid FRP plate including glass fibers were fabricated, and the effect of pre-stressed FRP composites on flexural strengthening of reinforced concrete (RC) beams was investigated. In total, eight RC beam specimens were fabricated, including one control beam (specimen N) without FRP composites and seven FRP-strengthened beams. The main parameters were type of FRP composite, the number of anchors used for pre-stressing, and thickness of FRP plates. As a result, the beam strengthened with pre-stressed FRP plate showed superior performance to the non-strengthened one in terms of initial strength, strength and stiffness at yielding, and ultimate strength. As the number of anchors and thickness of FRP plate (i.e., amount of FRP plates) increased, the strengthening effect increased as well. When hybrid FRP plates were pre-stressed, the strengthening effect was higher in comparison with pre-stressed single type FRP plate.