Design And Fabrication Of High Temperature Piezoelectric Accelerometer

With the development of sensor technology,piezoelectric accelerometer has been widely used in aerospace,electronic technology,transportation,civil engineering and other fields,and its performance requirements are increasingly higher and higher.At present,most of the common piezoelectric accelerometers on the market can only work at temperatures below 200 ?,which has been unable to be used in some high-temperature engineering.This thesis proposed a design method of piezoelectric accelerometer at high temperature,and designed a piezoelectric accelerometer that can work at high temperature.Firstly,the model of piezoelectric accelerometer is simulated and analyzed by ANSYS,and the relationship between the sensitivity of the sensor and the mass block is obtained.In the simulation process,it is found that the sensitivity increases with the increase of the weight of mass block.According to the simulation results of ANSYS and the size requirements of practical application,the model of piezoelectric accelerometer is designed by using AutoCAD and SolidWorks drawing software.This model is processed with Inconel alloy material.Piezoelectric element is langasite(LGS).Langasite(LGS)can work in high temperature environment of 900?.The piezoelectric accelerometer is assembled by machined parts and piezoelectric wafers and then tested.The performance parameters of the piezoelectric accelerometer can be measured by vibration experiments.Firstly,an experimental platform is built,which includes signal generator,power amplifier,standard shaking table,charge amplifier,data collector,computer and standard piezoelectric accelerometer.Shaking table is controlled by signal generator and power amplifier.The standard piezoelectric accelerometer and the prepared piezoelectric accelerometer are rigidly fixed on the shaking table.The charge sensitivity of the standard sensor is known.The two sensors are connected with the charge amplifier.The computer controls the data collector to collect the voltage signal amplified by the charge amplifier.The charge sensitivity of the prepared piezoelectric accelerometer can be obtained by analyzing and processing the output voltage signals of the two sensors amplified by charge amplifier.The vibration experiments of the piezoelectric accelerometer were carried out at room temperature and high temperature respectively.The test results at room temperature showed that the sensor has certain performance,but the sensor has a large noise signal.After filtering,the charge sensitivity of the sensor is obtained.It is found that the sensitivity increases with the increase of mass.The test results at high temperature showed that the charge sensitivity is about 0.5pC/g,and with the increase of temperature,the charge sensitivity does not change much,which indicates that the piezoelectric accelerometer can work normally at high temperature.