caa a22 4500 465751091 CHVBK 20180323111834.0 cr unu---uuuuu 170327e19900601xx s 000 0 eng 10.1007/BF02410234 doi (NATIONALLICENCE)springer-10.1007/BF02410234 Changes in modal parameters of a bridge during fatigue testing [Elektronische Daten] [H. Salane, J. Baldwin] The effects of high-cycle fatigue on the dynamic modal properties of a full-scale bridge test section are examined in this study. A span 30.5 m (100 ft) in length was salvaged from an interstate bridge for experimental testing to establish the fatigue performance of the retrofit procedures which could be used for future field repairs of the fatigue cracks. Horizontal cracks had formed in the webs of the twin bridge girders in the vicinity of the web-flange weld at or near the connections of the girders to the floor beams. An electrohydraulic vibration shaker was used to excite the test span in the torsional and bending modes to promote fatigue crack growth. In addition to the experimental evaluation of the retrofit procedures, the dynamic response characteristics of the test span during the high-cycle fatigue test were monitored. Experimental data have been used to establish mode shapes and modal damping ratios during the four-million-cycle fatigue test. Damping ratios ranged from 1.09 percent to 0.53 percent. Modal stiffnesses were calculated based on the experimental mode shapes. There is a modest correlation between the changes in stiffness and the observed cracking of the steel girders and the subsequent repairs. Society for Experimental Mechanics, Inc., 1990 Salane H. Civil Engineering Department, University of Missouri-Columbia, 65211, Columbia, MO aut Baldwin J. Civil Engineering Department, University of Missouri-Columbia, 65211, Columbia, MO aut Experimental Mechanics Kluwer Academic Publishers 30/2(1990-06-01), 109-113 0014-4851 30:2<109 1990 30 11340 https://doi.org/10.1007/BF02410234 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02410234 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Salane H. Civil Engineering Department, University of Missouri-Columbia, 65211, Columbia, MO aut NATIONALLICENCE 700 1- Baldwin J. Civil Engineering Department, University of Missouri-Columbia, 65211, Columbia, MO aut NATIONALLICENCE 773 0- Experimental Mechanics Kluwer Academic Publishers 30/2(1990-06-01), 109-113 0014-4851 30:2<109 1990 30 11340 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer