摘要
为探明服役后斜拉索钢丝疲劳行为的声发射(AE)特征,开展了服役后不同损伤程度钢丝疲劳试验的声发射监测,对比分析了不同工况下钢丝疲劳声发射信号活跃性,明确了钢丝疲劳损伤演化典型阶段,采用粒子群优化算法对钢丝疲劳损伤演化典型阶段的互相关信号参数进行了聚类分析,揭示了不同阶段的声发射信号波形规律。监测分析结果表明:服役后斜拉索钢丝疲劳强度随损伤程度的增大而减小,损伤程度越大的钢丝疲劳强度折减速度越快;在相同损伤程度下,应力幅增大导致钢丝疲劳寿命显著减小,声发射信号活跃性增强;根据声发射信号幅值、累计计数和累计能量指标,首次提出服役后斜拉索钢丝包含疲劳裂纹萌生、扩展至瞬时断裂全过程的六阶段疲劳损伤演化模型,揭示裂纹扩展阶段峰值频率占钢丝疲劳断裂全过程的比值超过90%的普适规律;基于上升时间等互相关参数,钢丝声发射信号聚类迭代收敛为4类,瞬时断裂信号波形特征为高幅值窄脉冲,释放大量能量。试验监测所得服役后斜拉索钢丝疲劳损伤演化中声发射信号参数和波形典型特征,可为钢丝的服役损伤状态评估和断裂预警提供技术保障。
In order to characterize the acoustic emission(AE)of fatigue behavior of existing stay cable wires,the fatigue tests were conducted using acoustic emission technology of existing stay cable wires with different degrees of damage.The AE signal activities of steel wires were compared under different operating conditions,and the typical stages of fatigue damage evolution were clarified.The waveform characteristics of each crack propagation and fracture stage were investigated,combining with particle swarm optimization algorithm clustering analysis of steel wires.The waveform patterns of AE signals at different stages were revealed.The results of monitoring and analysis show that fatigue strength of existing stay cable wires decreases with the increase of damage degree.The decrease speed of fatigue strength for steel wires is accelerated under the heavier damage.With the increase of stress amplitude,the fatigue life decrease,the AE signal activities of the steel wires increase under same damage degree.The whole process of fatigue crack initiation and propagation to fracture of cable existing stay cable wires divides into six stages based on the AE signal amplitude,cumulative counts and cumulative energy indicators.The ratio of the peak frequency of the crack propagation stage to whole fatigue fracture account for more than 90%.The AE signal clustering iterations of steel wires converge into four classes based on correlation parameters such as rise time.The waveform of fracture signal is characterized by narrow pulse of high amplitude,and large energy are released.The typical characteristics of AE signal parameters and waveforms in the fatigue damage evolution of existing stay cable wires can provide technical guidance for the service damage assessment and fracture warning of bridge steel wires.
作者
李熙
王春生
郑锦攀
史捷
LI Xi;WANG Chun-sheng;ZHENG Jin-pan;SHI Jie(School of Highway,Chang'an University,Xi'an 710064,Shaanxi,China)
出处
《中国公路学报》
北大核心
2026年第2期173-186,共14页
China Journal of Highway and Transport
基金
国家重点研究计划项目(2015CB057703)
中央高校基本科研业务费专项资金项目(300102214904)
三秦英才特殊支持计划创新创业团队项目。
关键词
桥梁工程
疲劳
声发射监测
斜拉索钢丝
聚类分析
疲劳损伤演化
bridge engineering
fatigue
acoustic emission monitoring
stay cable wire
cluster analysis
fatigue damage evolution
