Experimental Study On Stress Corrosion And Corrosion Fatigue Of Stay Cables Under Acid Rain Condition

Cable-stayed bridge with a beautiful structure,lightweight body and a unique mechanical characteristics is highly favored by bridge designers. China has also become a great nation built cable-stayed bridge. But stay cable stress corrosion and corrosion fatigue cable-stayed bridge has been the subject of research frontier, In this paper, stay cable system under acid rain accelerated test environment for support, By applying an alternating loads of cable-stayed static load and no load conditions as a comparison study of the corrosion process and cable-stayed corrosion and stress corrosion fatigue mechanism.In dealing with the test results to weight loss method to measure the different loading conditions of the corrosion rate of cable-stayed, While exposure to atmospheric corrosion rate, "China corrosion survey atmosphere" in the atmospheric corrosion monitoring points for the basic contrast conditions, Corrosion and corrosion rate obtained specimens in the accelerated test, Results in acid rain, while the corrosion rate environment homosexual cables in different forms of force and atmospheric corrosion rate; Through experimental study results: The corrosion rate of three specimens within five days of the specimen is consistent, In the 15-day trial of alternating loading conditions the corrosion rate of the test piece was significantly greater than the corrosion rate under static loading conditions of the specimen under no load conditions and specimen corrosion rate, The corrosion rates under static loading conditions of the specimen is greater than the corrosion rate under no load conditions specimen; By exposure to atmospheric corrosion data point of the southwestern region of the experimental results do comparison: Alternating loads corrosion rate corrosion rate every 5 days for a year under the actual atmospheric exposure, 15 days after the day of the corrosion rate was 1.95 under the actual atmospheric exposure, Corrosion rate of 30 per day for two days under the actual atmospheric exposure; Static loads corrosion rate of 5 days for a year under the actual atmospheric exposure, Corrosion rate of 5 days of exposure to the real atmosphere under 1.6 years, Static loads corrosion rate corrosion rate 30 days for 1.6 years under real atmospheric exposure; No corrosion rate under load after 5 days every day for the next exposure to the real atmosphere of a year, 15 days after the day of the corrosion rate of 1.46 years under real atmospheric exposure, 30 days after the day of the corrosion rate of 1.46 years under real atmospheric exposure. Simultaneously observed by a scanning electron microscope to stress corrosion and corrosion fatigue is different extensions and microcracks, And expansion of the formation conditions of crack nucleation and crack nanoscale, Corrosion fatigue crack extension condition primary and secondary cracks, And the development trend of small stress corrosion cracking and large cracks.The results of corrosion encoded MATLAB Ghost cellular automata simulation corrosion kinetics of corrosion under alternating load and static loading conditions of the specimen, so as to arrive relationship uniform corrosion and pitting; ANSYS12.0 finite element software to rely on cable-stayed corrosion under different finite element analysis, the relationship between stress and pit depth, the relationship between stress and pits pitch.In each of the above conclusions obtained, the proposed cable-stayed cable life prediction formula, Prediction formula calculated by the cable-stayed bridge in Chongqing,Failure to re-introduce the cable through each criterion above conclusions,at the same time an example to the south of Lake Taihu cable-stayed bridge life analysis.