The experiment of post-tensioned prestressed concrete beams under multi-level fatigue loading is accomplished. Crack developing situation and stiffness degradation is analyzed. A fatigue deflection program is generated to calculate the deflection of prestressed concrete beam under fatigue loading. The results indicate that crack develops under fatigue loading which value is less than cracking load, and the time of crack developing is related on loading level. Stiffness deteriorates fast in the first 150 thousand cycles, and then it deteriorates steadily. The deflection of fatigue loading beams is larger than which of static loading ones before cracking. However, with the increasing of load, as crack fully developed, the deflection of fatigue and static loading beams tends to be equal. The deflection of fatigue loading beams is 20% larger than static ones when failure. The results of stiffness degradation based fatigue deflection program fits favorably with test results within accepted limits, and it can be used for fatigue deflection calculation and forecast.
LEI Jun-qing;XIAO Yun;ZHANG Kun;LI Zhong-san;WANG Yue-yu.
Experimental study on fatigue performance of prestressed concrete beam under variable amplitude fatigue loading[J]. Journal of Vibration and Shock, 2013, 32(18): 95-100
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