Comparison of Sensor Output because of Base Plate Thickness and Shape Change of Piezoelectric Composite Sensor for Displacement Measurement

After the huge earthquake many steel structures were constructed using frame welded joints of welded construction and welded base. Steel structures are considered earthquake resistance structures however, many steel structures are constructed using frame-welded joints of fillet welded construction and welded column bases. These weld joints could result to have low capacity to absorb energy during earthquakes. Therefore, the application of structural health monitoring to the maintenance of infrastructures is extensively expected for new technology. However, in order to achieve practical utilization of new sensors, both accumulation of data and evaluation method to derive information about structural conditions from the measured data is highly required. To solve such a problem, we would like to measure the structure by health monitoring using a piezoelectric composite sensor. In this paper, measurements output voltage because using piezoelectric composite sensors, we recorded the sensor characteristics during measuring robot measurement because of changes in the thickness and shape of the base plate of the piezoelectric composite sensor. Structural FEM for sensor analysis is also introduced to evaluate the mechanism and influence of various environmental factors on the response of the structures.