# Dynamic Response of Electro-Mechanical Properties of Cement-Based Piezoelectric Composites
## 1 Introduction  
Concrete structures have become omnipresent in our lives. During their service life, the combined action of environment and loads lead to easy damage in concrete structure [1; 2; 3], they are not only subjected to quasi-static loads, but also to various dynamic loads. Nowadays, elucidating the mechanical properties of concrete structures under dynamic loads has become one of the research hotspots in the civil engineering field [4; 5]. Meanwhile, it has become a trend to rely on intelligent systems to implement health monitoring and damage forecasting methods for these structures [6; 7; 8]; however, it is difficult to practically apply these approaches [5; 6; 7]. Current piezoelectric smart materials exhibit several shortcomings, such as high costs, poor compatibility, and poor durability, which limit their applicability [5; 8; 9; 10]. The incompatibility of their mechanical properties with those of embedded pressure sensors and matrixes tend to facilitate internal cracks. The large size of pressure components, incompatibility with concrete materials, and high costs also hinder the applicability of piezoelectric smart materials in the field of concrete structures [11; 12; 13; 14]. Piezoelectric materials are widely used in structural damage diagnosis and health monitoring. Because of their low costs, fast response speeds, good reliability, suitable linear relationship, and decent electro-mechanical response characteristics, they also can be used in sensors and actuators [15; 16; 17; 18]. In recent years, the good matching performance of cement-based piezoelectric composite materials and concrete materials has led to the development of a multifunctional sensor suitable for civil engineering [8; 11; 19]. Compared with traditional piezoelectric materials, this novel sensor has two outstanding advantages: goodperformance and designability, and better compatibility with the concrete structure [20]. Therefore, in the field of engineering structure design, the cement-based piezoelectric ceramic sensor embedded in the reinforced concrete structure has received continuous attention for monitoring internal dynamic stress [21; 22]. According to the connection mode of the functional phase and matrix, cement-based piezoelectric composites can be categorized into more than ten models. Currently, three main composite materials are being researched and developed: 0-3, 1-3, and 2-2. Type 1-3 is a two-phase piezoelectric composite comprising a one-dimensional piezoelectric ceramic column, which is arranged in a three-dimensional connected cement matrix. Type 2-2 comprises a laminated piezoelectric ceramic phase and cement interlayer [23]. [PERSON] et al. [24] researched the electrical domain switching of piezoelectric ceramics in cement-based piezoelectric composites under quasi-static and dynamic compression loads. They revealed that the loading stress increases with a rise in the electrical domain switching. [PERSON] et al. [25] used a first-stage light gas gun to study the output electrical signals of PZT-5H under different loading rates. They demonstrate that at low loading rates, the output electrical signal of PZT-5H maintains a linear relationship with the applied load. At high loading rates, the efficiency associated with the conversion of kinetic energy to electrical energy for PZT-5H is low. [PERSON] et al. [26] used a Split Hopkinson pressure bar (Ningbo University, Noingbo, China) (SHPB) device to perform single and multiple impact compression tests on type 1-3 cement-based piezoelectric composites; they found that the material has a significant strain rate effect, while showing that it is a strain rate sensitive material. Meanwhile, the linear electro-mechanical response of the material has a critical point. [PERSON] et al. [27] performed a dynamic analysis of cement-based piezoelectric composites by using the displacement method and found that the piezoelectric elastic theory is applicable to cement-based piezoelectric composites under different strain rates.