U肋带内隔板钢桥面疲劳性能研究

针对正交异性铁路钢桥面构造细节,开展U肋钢桥面疲劳性能研究,进行了两个足尺钢桥面构件的静载和高周疲劳承载试验,其中试件DECK1纵肋无内隔板,试件DECK2在横梁腹板处纵肋内设置内隔板.试验研究结果表明:纵肋内隔板可有效改善纵肋腹板和横梁帽孔细节部位的受力,提高钢桥面的疲劳强度;与横梁帽孔交汇处的纵肋腹板为疲劳裂纹易发处,两个构件均在此处出现水平向疲劳裂纹;采用有限元计算模型,分析研究了纵肋内增加内隔板对钢桥面受力的影响,计算结果与试验结果吻合.

Fatigue Performance of Orthotropic Steel Bridge Decks with Inner Diaphragm in U rib

Fatigue performance of orthotropic steel decks with U rib was investigated based on the specific constructional detailing of the steel railway decks. Two full scale specimens, DECK1 which had the inner diaphragms in the U ribs, and DECK2 which did not have the inner diaphragms were tested under the static loading and the high cycled loading. Test results show that inner diaphragms in the U ribs help to redistribute stress in web of the rib and stress in diaphragm of the crossbeam, and hence to improve the fatigue strength of rib to diaphragm detail in the orthotropic steel railway decks. Fatigue cracks initiates very likely from the toe of the rib to diaphragm welds, and both specimens develop horizontal cracks in the web of rib at the position close to the rib to diaphragm connections. Finite element (FE) model of the decks is developed and the results agree well with the test results. Influences of the inner diaphragms in the U ribs on the stress state and the fatigue performance of the deck were analyzed.