Abstract
In recent years, there is considerable interest in the Structural health monitoring. This is a technique to diagnose and evaluate the damage and deterioration of a structure by attaching sensors to the structure, and is useful for judging whether building can be reused or not at that time of a disaster such as an earthquake. There are several types of sensors such as piezoelectric type, optical fiber and strain gauge type and piezoelectric sensors are very suitable for this purpose because they do not require an energy source considering that they produce electrical power by themselves. However, the application range of piezoelectric ceramics used for piezoelectric sensors is narrow because of its fragility. Then, the researches and developments of the piezoelectric ceramics embedded in the matrix that has excellent mechanical strength are carried out. The metal-core piezoelectric fiber/aluminum composite was developed by Asanuma et al. to overcome the problems associated with piezoelectric ceramics, such as poor mechanical properties, reliability; brittleness and low fracture strain. The fracture strain of piezoelectric ceramics fiber significantly improved due to residual compressive stress caused by difference of coefficient of thermal expansion between the ceramics and the matrix during embedding process. However, there is few statistical data on the mechanical properties of piezoelectric ceramic fibers, and the improvement in the properties due to the embedding has not been quantitatively evaluated. In this study, to overcome this problem, the simplified model of metal matrix piezoelectric composite was fabricated and used to compare strengths before and after embedding by 3-point bending test. As a result, it is found that Weibull parameters of piezoelectric ceramics are improved by embedding in the matrix.
