Experimental Study Of Stay Cable Electrochemical Corrosion Fatigue Under Alternating Stress State

Cable-stayed bridge across the large capacity due to simple and beautiful form and structure, has gradually become a modern form of long-span bridge structure important, but the stay cable corrosion was restricted to the span cable-stayed span greater development. Currently, domestic and corrosion on the stay cable conducted a lot of research, the main corrosion research methods include: atmosphere to stay cables completely exposed natural corrosion test and indoor accelerated corrosion on the cable-stayed simulation. Cable-stayed indoor accelerated corrosion test many different types of simulation,From the simulated environment can be divided into accelerated salt spray corrosion test simulation environment, accelerated corrosion tests simulated acid rain environment, accelerated corrosion electrochemical simulation environment, but these are mainly accelerated corrosion simulations carried out in the absence of stress, without considering the impact of stress on the cable corrosion. In this paper, through the cable-stayed alternating stress state electrochemical corrosion fatigue test simulation to analyze the alternating load on cable-stayed corrosion.By galvanized steel in a different state of stress, accelerated corrosion tests simulate different corrosion cycle, come to the same period of corrosion, galvanized steel strand in alternating stress, corrosion of galvanized steel fastest, under the same state of stress, corrosion of galvanized steel cycle is longer, more severe corrosion, then the cable-stayed in different stress corrosion corrosion cycle different state inference, Ansys through finite element simulation analysis of the cable-stayed under static stress corrosion conditions and alternating stress state, draw alternating stress corrosion impact on cable-stayed situations include the following aspects:① Nnder the same kind of stress, stress corrosion outer strand cable segment is greater than the value of the internal stress of the strand, strand cable outer segment without corrosion stress value is less than the value of the internal stress Strand; description corrosion leads to the redistribution of the force of cable cross-section, the outer strand stress value increases.② Nnder the same kind of stress state, along the length of the cable, not corrosion-sectional stress distribution segment is relatively stable no fluctuations, however, corrosion in the cable section, the peak stress occurs, i.e., the stress concentration; description corrosion leads to corrosion of the cable segment of stress concentration.③ Nnder different stress state, the greater the impact of alternating stress corrosion of the outer segment of cable strand stress the difference between stress and internal strand, along the cable length, cable section peak stress corrosion occur is greater; description alternating stress corrosion stress distribution cables, and the emergence of a greater impact on the local stress concentration.