1-3型水泥基压电复合材料在冲击载荷下的力电响应及损伤的实验研究

发布时间：2018-11-10 16:35

【摘要】：伴随社会经济的不断发展,采用智能传感监测系统的在线健康监测和预报,已在重要混凝土建筑工程中广泛应用。水泥基压电复合材料拥有低声阻抗、低机械品质因数以及高机电耦合系数等特点。这种新型的功能材料可以较好的解决一般智能材料与混凝土结构材料兼容性不佳的问题;且对湿度不敏感,能长久工作在混凝土环境中。智能材料若失去本要实现的特定功能,则称之为失效。植入于混凝土结构中的智能传感器也将随结构体一起受到静态或动态载荷的作用,发生传感信号异常,甚至失效,因而智能传感材料耦合性能的研究引起了学界的广泛关注。本文以PZT5H为功能体,普通硅酸盐水泥为基体,采取切割-浇注法制备了1-3型水泥基压电复合材料,并对PZT5H材料和1-3型水泥基压电复合材料分别在准静态和动态载荷下的力电响应特性及其材料损伤失效规律进行了实验研究与分析。利用MTS伺服试验机和分离式Hopkinson压杆装置(SHPB)分别对PZT5H和1-3型水泥基压电复合材料进行准静态压缩实验和动态压缩实验。由实验可得:冲击载荷条件下,PZT5H和1-3型水泥基压电复合材料的电位移与应力均具有较好的力电响应关系;且随应变率的增加,在产生相同应变或应力下,所对应的应力或电位移也分别增加;同时,在一定应变率范围内,随应变率的增加,试样在冲击载荷下的失效电位移也增加。在准静态多次加载条件下,由于电畴反转现象,两种试样的电位移幅值均随着加载次数的增加而减少;在多次循环加载下,随循环次数的增加材料的残余应变累积增加,电位移幅值和剩余电位移均逐步减小,压电材料的压电性能也相对减弱,直至力电耦合响应失效。
[Abstract]:With the development of social economy, the on-line health monitoring and forecasting using intelligent sensor monitoring system has been widely used in important concrete construction projects. Cement based piezoelectric composites have the characteristics of low impedance, low mechanical quality factor and high electromechanical coupling coefficient. This new type of functional material can solve the problem of poor compatibility between general intelligent materials and concrete structure materials, and it is insensitive to humidity and can work in concrete environment for a long time. A smart material that loses a specific function that it is intended to achieve is called a failure. The intelligent sensors implanted in concrete structures will also be subjected to static or dynamic loads along with the structure, resulting in abnormal or even invalid sensing signals. Therefore, the research on the coupling properties of intelligent sensing materials has attracted wide attention in the academic field. In this paper, 1-3 type cement-based piezoelectric composites were prepared with PZT5H as functional body and ordinary Portland cement as matrix. The mechanical and electrical response characteristics of PZT5H and 1-3 type cement based piezoelectric composites under quasi-static and dynamic loading respectively and the damage failure law of the materials are studied and analyzed experimentally. The quasi static compression experiments and dynamic compression experiments of PZT5H and 1-3 type cement based piezoelectric composites were carried out by using MTS servo testing machine and separate Hopkinson compression bar device (SHPB) respectively. The experimental results show that the electric displacement and stress of PZT5H and 1-3 type cement based piezoelectric composites have a good electromechanical response under shock loading. With the increase of strain rate, the corresponding stress or electric displacement increases respectively under the same strain or stress, and the failure electric displacement increases with the increase of strain rate in a certain range of strain rate. Under quasi-static multi-loading condition, the amplitude of electric displacement decreases with the increase of loading times due to domain reversal. Under repeated cyclic loading, the residual strain accumulation increases with the increase of cycle times, the amplitude of electric displacement and residual electric displacement decrease gradually, and the piezoelectric properties of piezoelectric materials weaken relatively, until the electromechanical coupling response fails.
【学位授予单位】：宁波大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB33

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