基于智能压电传感机械阻抗的混凝土结构钢筋锈蚀损伤识别

Corrosion damage of reinforcement in concrete structures would induce concrete spalling and performance deterioration of steels even the premature failures of the whole structure, if it is not found in time. Timely accurate detection of structural corrosion damages has been always a challenge in concrete structural engineering discipline.Intelligent piezoelectric (PZT) electro-mechanical coupling and sensing based structural mechanical impedance (SMI) method has been proved to be an efficacious method for identifying corrosion damages of concrete structures. However, existing impedance model remains limits in the accuracy of detecting corrosion damage. This project first formulates an accurate three-dimensional PZT-bonding layer-structure coupling impedance model, and then develops a wireless PZT-sensing technique to monitor concrete structural corrosion damages based on the model, in which SMI signature is extracted. Bayesian method is also introduced to select an optimal equivalent-mathematical model for SMI. Finally, structural mass loss and stiffness loss is accordingly calculated to formulate an assessment method for quantifying reinforcement corrosion damages based on the equivalent model. Moreover, numerical simulation, experimental study and practical engineering application are adopted to fully validate the proposed method. The research in this project provides new solutions for on-line, high-precise identification on concrete structural corrosion damages, which is of great significance both in the theoretical developments and engineering applications of the discipline.

混凝土结构中钢筋的锈蚀损伤会引发混凝土胀裂和钢筋性能劣化，从而导致结构过早失效破坏，及时准确地识别钢筋锈蚀损伤一直是混凝土结构工程学科的挑战性难题。基于智能压电陶瓷(PZT)电机耦合传感的结构机械阻抗(SMI)法被证明是一种有效的混凝土结构钢筋锈蚀损伤识别方法，但目前的阻抗模型在锈蚀损伤的识别精度上仍存在缺陷。本项目首先建立植入式PZT-粘结层-结构耦合三维阻抗精确模型；然后利用模型开发无线PZT传感技术监测混凝土结构内部钢筋锈蚀损伤并提取结构机械阻抗，引入贝叶斯理论选择合适的结构机械阻抗等效数学模型；最后基于等效模型计算结构质量、刚度损失等信息，建立混凝土结构钢筋锈蚀损伤的量化评估方法；进一步通过数值模拟、试验研究以及实际工程应用探讨所提方法的精确性和有效性。项目的研究成果为钢筋混凝土结构锈蚀损伤的在线准确识别提供新的研究思路，对学科的理论研究及工程应用具有重要意义。

混凝土结构中钢筋的锈蚀损伤会引发混凝土胀裂和钢筋性能劣化，从而导致结构过早失效破坏，及时准确地识别钢筋锈蚀损伤一直是混凝土结构工程学科的挑战性难题。基于智能压电陶瓷(PZT)电机耦合传感的结构机械阻抗(SMI)法被证明是一种有效的混凝土结构锈蚀损伤识别方法，但目前的阻抗模型在锈蚀损伤的识别精度上仍存在较大缺陷。本项目首先建立植入式PZT-粘结层-结构耦合三维阻抗精确模型；然后利用模型开发无线PZT传感技术监测混凝土结构内部钢筋锈蚀损伤并提取结构机械阻抗，引入贝叶斯理论选择合适的结构机械阻抗等效数学模型；最后基于等效模型计算结构质量、刚度损失信息，建立混凝土结构钢筋锈蚀损伤的量化评估方法；进一步通过数值模拟、试验研究以及实际工程应用探讨所提方法的精确性和有效性。项目的研究成果为钢筋混凝土结构锈蚀损伤的在线准确识别提供新的研究思路，对学科的理论研究及工程应用具有重要意义。