Study On Preparation And Performance Of Stainless Steel Thick-film Strain Sensor

Strain sensors play an important role in the field of structural health monitoring in civil engineering.However,the current mainstream strain sensors have some shortcomings,such as the poor durability of strain gages,the high cost of vibrating wire sensors and only suitable for measuring static strain,the expensive fiber Bragg grating strain sensors,and the cumbersome installation and control.In view of this,in order to enrich the types of strain sensors and provide a new method for strain monitoring,this article combines thick film resistors,which also have excellent durability and high cost performance,with stainless steel to explore the preparation of stainless steel substrate thick film strain sensors.Through the research on the performance of thick film resistors,the structural design of sensor conversion elements and the performance of the designed and tested sensors.The main work and research results are as follows:(1)Through the preparation of stainless steel substrate thick film r esistor and basic performance testing.The insulation process of the stainless steel substrate with the layered firing dielectric layer was selected and the stability of the thick film resistor was ensured to understand the substrate to a certain thickness.The strain coefficient of the thick film resistor was measured as 10 and the temperature coefficient was 66 ppm / ?.Exploring the preparation of a thick film resistor with a temperature coefficient of 24 ppm / ° C that reduces the influence of temperature,and then conducting a stability test on it,showing good resistance value stability;(2)The strain range and sensitivity of the strain sensor under the two types of sensitive element structure are analyzed.It was found that the rectangular structure with enlarged range is smaller than the yield strain value of the substrate;the double-loop structure with enlarged range can design a sensor with a larger range than the yield strain value of the substrate.The finite element simulation verified the correctness of the theoretical design of the double-ring structure,and the optimization method of changing the line width of the vertical beam of the ring structure verified that the effect of reducing the vertical size of the base structure was not obvious;(3)Designed and prepared two ring-type stainless steel thick-film strain sensors with amplifying range of two sensitivity series with the same strain ranges of 3000??.The comprehensive performance test of the sensor shows that the linearity,mechanical lag,fatigue,design linear working range,zero drift,repeatability and other performance are good.