We reported a sensor, designed based on the specific working modes of piezoelectric, to characterize the three-dimensional (3-D) stress state in concrete. The sensor contains 6 piezoelectric elements: 3 elements working in normal mode to measure the normal stress, and 3 elements working in shear mode to measure the shear stress. Cement-based piezoelectric composite, fabricated by cutting-filling method, was used to fabricate the sensor, as it has better mechanical compatibility with concrete than piezoelectric ceramics. By embedding the sensor into a cement mortar column, we systematically characterized its performance under dynamic uniaxial load from 3.0 MPa to 7.5 MPa with frequency from 1 Hz to 20 Hz. Results demonstrate that the sensor can measure the 3-D stress state in concrete well, and has good linearity, high sensitively, and excellent working bandwidth. The cross sensitivities of the sensor were also calculated and discussed.

中文翻译：

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设计用于表征混凝土中三维应力状态的水泥基压电复合传感器

我们报告了一种基于压电的特定工作模式设计的传感器，用于表征混凝土中的三维（3-D）应力状态。该传感器包含6个压电元件：3个在正常模式下工作以测量法向应力的元件，以及3个在剪切模式下工作以测量剪切应力的元件。通过切割填充法制造的水泥基压电复合材料被用于制造传感器，因为它与混凝土的机械兼容性比压电陶瓷更好。通过将传感器嵌入水泥砂浆柱中，我们系统地表征了其在3.0 MPa至7.5 MPa动态单轴载荷，频率为1 Hz至20 Hz的情况下的性能。结果表明，该传感器能够很好地测量混凝土的3D应力状态，并具有良好的线性度，高灵敏度，以及出色的工作带宽。还计算并讨论了传感器的交叉灵敏度。