CAJ | 학술논문

为评估钢桥面板的疲劳寿命，在某大桥钢箱梁1/4跨截面的顶板与U肋连接焊缝处和横隔板弧形缺口处布置应力测点，进行24 h疲劳应力监测。根据实测数据，利用雨流计数法计算得到疲劳应力谱，并基于BS 5400规范对各应力测点的疲劳损伤状态进行评估。结果表明：横隔板弧形缺口周边测点的应力水平相对较高；各应力测试点以低幅值应力循环为主，其中应力幅为2~10 MPa的循环次数占90%以上，但最大应力幅值均超过了BS 5400规范规定的产生疲劳损伤的极限值。疲劳寿命分析表明，顶板与U肋纵向连接焊缝过焊孔处易产生靠近顶板部位的疲劳裂纹，横隔板与U肋腹板连接焊缝的疲劳寿命较低。
위평고강교면판적피로수명，재모대교강상량1/4과절면적정판여U륵련접한봉처화횡격판호형결구처포치응력측점，진행24 h피로응력감측。근거실측수거，이용우류계수법계산득도피로응력보，병기우BS 5400규범대각응력측점적피로손상상태진행평고。결과표명：횡격판호형결구주변측점적응력수평상대교고；각응력측시점이저폭치응력순배위주，기중응력폭위2~10 MPa적순배차수점90%이상，단최대응력폭치균초과료BS 5400규범규정적산생피로손상적겁한치。피로수명분석표명，정판여U륵종향련접한봉과한공처역산생고근정판부위적피로렬문，횡격판여U륵복판련접한봉적피로수명교저。
In order to evaluate the fatigue life of a steel bridge deck, stress measuring points were set near the weld of the roof connected to the U-rib and the arc-shaped notch of the diaphragm plate across a quarter of a bridge ’ s steel box girder, and the fatigue stress was monitored for 24 hours. According to the measured data, the fatigue stress spectra were calculated with the rain-flow counting method. Based on the BS 5400 specification, the fatigue damage state of the stress measuring points was evaluated. The results show that the stress level of the measuring points near the arc-shaped notch of the diaphragm plate was relatively high. Each stress measuring point was mainly a low-rising stress cycle and the cycles of 2 to 10 Mpa stress amplitude accounted for more than 90%. However, the maximum stress amplitude exceeded the limit of fatigue damage stipulated by the BS 5400 specification. Fatigue life analysis shows that fatigue cracks in the weld of the roof connected to the U-rib easily occurred near the roof area at the welding hole, and the fatigue life of the weld of the diaphragm plate connected to the U-rib’ s web was short.