To address the issue of limited sensor reliability in extreme environments due to thermal stress,leading to sensor zero drift,temperature drift and even failure,a thermal stress calculation method and finite element model for high-temperature piezoelectric force sensors based on thermal-structural coupling.Based on the equilibrium equation and the thermal-elastic theory,the physical equation of thermoelastic mechanics of the sensor is established,and the impact of packaging material and temperature on the thermal stress of the piezoelectric force sensor is analyzed.By examining the thermal stress distribution of the piezoelectric force sensor in high-temperature environments,the areas of stress concentration within the sensor are identified.Tracing back the thermal stress of the sensor reveals that thermal mismatch stress arises from the disparity in the thermal expansion coefficients between the packaging material and the crystalline material.The random vibration power spectral density is converted into an acceleration time-domain signal,and the sensor's thermal stress is analyzed using a multi-physics coupling method,yielding a maximum stress of 134.61 MPa,which is below the material's yield strength by 300 MPa,confirming the sensor's reliability in high-temperature,high-pressure,and random vibration environments.An examination of the impact of alumina and zirconia insulation on the sensor's maximum thermal stress shows that at 420℃,the maximum thermal stress of the alumina-insulated sensor is 9.18 MPa lower than that of the non-insulated sensor and 79.31 MPa lower than that of the zirconia-insulated sensor.The research provides insights for reducing thermal stress in sensors in high-temperature environments.
NETL
NSTL
万方数据
