In this paper, the experimental study and finite elements analysis were conducted on homogeneous and dissimilar metals single lap-shear bonded joints to investigate the factor that affect the joint failure load. It was found that factors which have the significant effects on the failure load of the joint was stiffness of the adherends. And from experimental results, it can be confirmed that the failure load increases linearly with overlap length increases. And the failure load of dissimilar metal joints is approximately 1KN(10 ～17%) larger than homogeneous metal joints. In order to confirm this phenomenon, the stress distribution and strain distribution of the specimens were analyzed through the finite element analysis. The difference between homogeneous metals joints and dissimilar metals joints is that stress and strain in adhesive are concentrated at the end of the overlap zone close to aluminium which has lower rigidity than aluminium in case of dissimilar metals joints. From high rigidity of steel, the stress concentration in bonds are decreased and it cause increase of the failure strength at dissimilar metal joints.

Type 304 stainless steel 시편에 느슨하게 붙어있는 분말에 대한 초음파 제염 거동을 조사하였다. 매질을 물, PFC 및 의 음이온 계면활성제를 함유한 PFC 용액으로 변화시킴에 따라 제염계수는 20, 50 및 200으로 증가하였다. 제염계수에 차이가 생기는 이유를 초음파 매질의 표면장력 및 양으로 하전된 산화물 표면과 음이온 계면활성제 사이의 상호작용에 기인한 것으로 설명할 수 있었다. 음이온 계면활성제를 함유한 PFC 용액 내에서 분말로 오염된 평면 시편, 파이프 시편, 틈새 시편 및 용접 시편에 대한 초음파 제염 효과를 관찰하였다. 연구된 모든 시편에 대해, 대부분의 오염물이 완벽하게 제거되는 것으로 나타났다. 길이가 6cm인 파이프 시편에 대해서는 오염물의 가 제거되었다.

The purpose of this study was to evaluate the effects of Ca(OH)2 and CO2 additions on the corrosion of metal coupons (ductile iron, galvanized steel, copper and stainless steel). Corrosion rate and released metal ion concentration of ductile iron and galvanized steel was decreased by adjusting alkalinity, calcium hardness and pH with Ca(OH)2 & CO2 additions named CCPP (Calcium Carbonate Precipitation Potential) index control process. But the effects of Ca(OH)2 & CO2 additions on copper and stainless steel were less than those on ductile iron and galvanized steel. When ductile iron coupon was exposed to water treated with Ca(OH)2 & CO2 additions, the main components of corrosion product formed on its surface were CaCO3 and Fe2O3 or Fe3O4, which often reduce the corrosion rate by prohibiting oxygen transport to the metal surface.