Finite Element Simulation And Uncertainty Analysis Of Microsensor

Microsensor is one of the core elements in the inertial navigation and guidance system.The accuracy of navigation and guidance is determined by the performance.The micro-sensors used in aviation airborne inertial navigation systems require long service hours,and the working environment temperature is constantly changing.This requires a high stability of the micro-sensors' output;but the output is quite sensitive to the temperature.The influence of temperature on the stability of its output has not yet been summarized,making it difficult to accurately compensate for it,and seriously affecting the performance of micro-sensors and the yield of products.For now,one of the challenges in the development of microsensor design is the thermal instability of its output.Therefore,it is of great engineering value and significance to study the influence rule of temperature on the output of microsensors.In this paper,micro-sensors are taken as the research object,and the mechanism of thermal instability of micro-sensors and the law of progressive transfer of uncertainties in micro-sensors are studied.The main work is as follows:(1)The development status and working principle of micro-sensors are introduced.The current problems of thermal instability are described in detail.The composition of micro-sensors is decomposed,and the influence of the connection mode on the performance of micro-sensors is analyzed in depth.A brief description of the material properties of its components is given,too.(2)The related basic theory of viscoelasticity theory and the time-temperature equivalence principle are introduced.The Kelvin model is used as an example to illustrate the relationship between the strain generated when the viscoelastic material is subjected to cyclic stress loading and the instability of the output of the microsensor.Based on the viscoelastic theory and the time-temperature equivalent principle,the mathematical expression of the one-dimensional thermo-viscoelastic constitutive model of the adhesive in the micro-sensor was deduced.Through the expansion of the analogy,the three-dimensional thermo-viscoelastic constitutive model was deduced.(3)The CAE model of the microsensor is established based on the simulation software ABAQUS.The simulation flow of the microsensor is established.The stress relaxation experiment of the adhesive in the miniature sensor is made by the thermomechanical analyzer.The software Fortran was used to compile the subroutine UMAT based on the deduced constitutive model.The simulation software ABAQUS was used to call the subroutine to perform the numerical simulation analysis of the microsensor and reproduce the thermal instability phenomenon of the microsensor.(4)Sensitivity analysis of uncertain factors in assembling process of microsensors can be calculated by the soboOl method.The factors that have a great influence on the output performance of the micro sensor in the assembly process are obtained.The uncertainty propagation model of microsensor based on arbitrary chaos polynomial is established and the propagation law of uncertainty factors in the micro-sensor during the assembly process is summarized which can provide theoretical guidance for the subsequent optimization of micro-sensors.