The sealing performance of box-shaped bolted flanged joints using silicone sealant instead of formed gasket under steady temperature state

摘要

It is secure to improve the sealing performance or bolted flanged joints subjected to internal pressure. These joints have been used under various temperature state as well as internal pressure. Hence damages of the structure due to thermal stress at the interfaces will occur. In addition, thin wall flanged joints have been used in mechanical structures such as oil-pan structure in automobile. In the thin wall structure, it is necessary to obtain the better sealing performance. However a few investigations dealt with the sealing performance of the thin wall flanged structure under thermal conditions. In thin study the interface stresses of the thin wall box-shaped flanged bolted joint with the silicone sealant under steady temperature state were analyzed by using FEA when internal pressure was applied to the connection. The thin wall flanges were fastened by M8 bolts and nuts with an initial clamping force after being jointed by the silicone sealant. Furthermore, the effect of bolt positions, liner thermal expansion coefficient and so on are examined on the sealing performance. The experimental results of thermal stresses are in fairly good agreements with the numerical results. It is found that the effect of the thermal exposure is greater than that of internal pressure on the interface stress distributions. In other words, it means that the thermal condition affects to the sealing performance substantially comparing with internal pressure in this case. In addition, the sealing performance was found to be better in the joint using the silicone sealant than that using the formed gasket.