摘要
针对桥梁疲劳损伤累积过程中的大量不确定性因素,基于Miner线性累积损伤理论提出车辆荷载作用下大跨斜拉桥的疲劳可靠度评估方法。通过"影响面"计算得到车辆荷载作用下各斜拉索的时点应力,采用"雨流计数法"统计斜拉索的应力幅和循环次数。在此基础上,对车辆荷载作用下斜拉索的疲劳可靠度进行分析。结果表明:斜拉索应力随机过程可采用Poisson过程描述;车辆荷载作用下的斜拉索疲劳可靠指标为7.19~17.57,靠近索塔处的斜拉索疲劳可靠指标较大,远离索塔处的斜拉索疲劳可靠指标较小。
Taking into account the uncertainties in the process of fatigue damage accumulation for fatigue reliability analysis of bridge,a fatigue reliability assessment method for the long-span cable-stayed bridge under vehicle loads was proposed based on Miner linear fatigue-damage accumulation theory. According to the location of the random traffic flow on the bridge,the influence surface was used to calculate the arbitrary-stress of stay cable produced by random vehicle,and then the rain flow counting method was employed to obtain the amplitude tensile-stress range and number of constant-amplitude-stress cycle of stay cable. By using the model of fatigue reliability of stay cable established in the paper,the fatigue reliability index of stay cable in design reference period was calculated. The results showed that the stay cable stress could be modeled by Poisson stationary stochastic process. The stay cable reliability index was 7. 19 ~ 17. 57 for the long-span cable-stayed bridge under random vehicle load,and the reliability index of stayed-cable closing to the cable tower would be larger,and vice versa.
出处
《工业建筑》
CSCD
北大核心
2017年第6期163-167,共5页
Industrial Construction
