压电波动法预应力混凝土锈胀监测数值模拟

Numerical Simulation of Monitoring Rust Expansion of Prestressed Concrete Using Piezoelectric Wave Method

受工作环境、服役时间等因素影响,预应力钢绞线将发生锈蚀,导致混凝土锈胀开裂,严重威胁着结构的耐久性。为了解构件的锈蚀开裂情况,提出了一种基于压电波动法监测预应力混凝土锈胀开裂的有限元模拟方法。运用Abaqus构建了基于压电波动法的预应力混凝土锈胀开裂细观模型,该模型由砂浆、骨料、构造钢筋、预应力钢绞线及压电陶瓷等组成。分析了压电-锈蚀PC构件机电耦合过程,实现了基于压电应力波法监测钢绞线锈蚀膨胀引发混凝土裂缝发生及发展的整个过程。研究结果表明,从锈蚀开始到轻微锈蚀阶段,压电电压信号峰值升高13.4%,首波接收时间缩短1.2%;从轻微锈蚀阶段到加速锈蚀阶段,直至理论锈蚀率阶段,受锈蚀裂缝影响,压电电压信号峰值降低,首波接收时间延长,电压变化分别减少6.6%和48.6%,首波接收时间分别增加6.0%和29.8%。通过验证试验和模型在各阶段峰值电压的对比,其差值小于0.32 mV,验证了压电波动法监测预应力混凝土锈胀有限元模型的可靠性。

Inherent to the influence of multiple factors,including environmental conditions and service time,prestressed steel strands corrode over time.This leads to concrete rust expansion and crackingand poses a critical threat to structural durability.To monitor the extent of cracking in this context,this study proposes a finite element simulation method based on piezoelectric wave propagation.Using Abaqus,a micro-scale model comprising mortar,aggregate,structural rebars,prestressed steel strands,and piezoelectric ceramics was constructed.By analyzing the electromechanical coupling process,concrete crack development induced by steel strand rust expansion was comprehensively monitored.The findings demonstrated that as corrosion progressed from the onset to mild stages,the piezoelectric signal-peak voltage increased by 13.4%,while the first wave reception time decreased by 1.2%.From the mild to accelerated corrosion stages,and up to the theoretical corrosion rate stage,influenced by corrosion-induced cracks,the peak voltage decreased,and the first wave reception time extended.Specifically,the voltage decreased by 6.6%and 48.6%,and first wave reception time increased by 6.0%and 29.8%,respectively.Based on the results of validation experiments,with discrepancies of less than 0.32 mV,the reliability of the proposed piezoelectric wave propagation method for monitoring prestressed concrete rust expansion using finite element models was confirmed.