Improved inertia moment method of dynamic speckle analysis and its application

Abstract

The aim of this paper is to present a novel inertia moment algorithm meanwhile use it to investigate the stress corrosion initiation stage of an aluminum alloy. The specimens are Al-2A12 alloy with thickness of 2mm which are immersed in the 3.5% sodium chloride solution. Three-point bending system is employed under displacement loading mode. The center displacement is 2mm, 2.5mm and 4mm, respectively. Meanwhile in order to observe the stress corrosion process, the solution temperature increases from 20.9 to 61.3 degrees centigrade. Average intensity method is recommended to contrast due to its validity for corrosion analysis. The results show at room temperature, the material is not prone to stress corrosion. General electrochemical corrosion is a major role and the process is comparatively moderate. Stress corrosion appears when the temperature has increased. It is a phenomenon of localized corrosion and exhibits asymmetric property. Accompanied with the corrosion process developed, this kind of asymmetric property is increasingly apparent from three-dimensional results.