基于压电传感器的混凝土损伤检测数值模拟

Numerical Simulation of Concrete Damage Detection Based on Piezoelectric Sensor

该文基于ABAQUS有限元软件建立了压电陶瓷材料与混凝土的机-电多物理场耦合数值分析模型,对压电波动法检测混凝土裂缝和弹性模量测定进行数值模拟,探究其损伤识别的机理。采用C3D8E压电单元模拟压电陶瓷(PZT),采用C3D8R单元模拟混凝土梁,采用三维时域粘弹性人工边界消除边界对应力波的反射。模拟结果表明,嵌入式PZT片激发的应力波包括纵波和剪切波,其中剪切波的幅值比纵波大,传播速度比纵波慢。以信号相对能量(D_i)作为损伤程度判别因子,其值随着裂缝的深度增加而降低。将数值模拟计算的D_i和混凝土的动弹性模量(E_d)与试验结果进行对比,符合较好,说明有限元方法可以有效地解决该类问题。

Based on the ABAQUS finite element software, a numerical analysis model of mechanical-electrical multi physics field for piezoelectric ceramics and concrete is established in this paper. A numerical simulation study on the concrete cracks detection and elastic modulus determination by the wave propagation method is carried out, and the mechanism of damage identification by piezoelectric wave method is investigated. The C3D8E piezoelectric elements are used to simulate the piezoelectric ceramic （PZT）, and the C3D8R elements are used to simulate the concrete beam. The three-dimensional visco-elastic artificial boundary in time domain is adopted to eliminate the reflection of the stress wave on the boundary. The simulation results show that the stress waves excited by the embedded PZT patch are composed of the longitudinal wave and shear wave. The amplitude of the shear wave is larger than that of the longitudinal wave, and the propagation velocity is slower than that of the longitudinal wave. The relative energy of signal （Di） is used as the discriminant factor of damage degree, and its value decreases as the depth of the crack increases. The relative energy of signal （Di） and the dynamic modulus of elasticity （Ed） of the concrete obtained by numerical simulation are compared with the experimental data, and the results are in good agreement, indicating that the finite element method can effectively solve the problem.