电阻应变式传感器应变传递影响因素分析

Analysis of strain transfer influence factors of resistance strain sensor

为研究电阻应变式传感器的应变传递机理,基于剪滞理论建立电阻应变式传感器应变传递的三维模型,推导出应变传递函数,利用有限单元法模拟出传感器各部分的应变分布并与理论值进行比较。具体分析粘接层几何参数和力学性能对应变传递的影响。结果表明:在测量过程中,应变片敏感栅中间部位所受的应变最大,并向两端逐渐递减直至为0;敏感栅、基底和胶结层两端均不受力的作用;基底与敏感栅、胶结层与基底之间存在应变过渡区;胶结层的横向宽度越长、厚度越薄和剪切模量越大,敏感栅有效区域长度越长,越有利于应变传递。研究结果对传感器应变片的选择和粘贴具有理论指导意义。

In order to study the strain transfer mechanism of the resistance strain sensor, a 3D model for strain transfer of resistance strain sensor based on the shear lag theory was built and the strain transfer function was derived. The strain distribution of the sensor was simulated via the finite element method, and it was compared with the theoretical value, and then the influence of geometrical parameters and mechanical property of bonding layer on strain was analyzed. The results show that the strain in the middle of sensitive grid of strain gauge is the largest and gradually decreases to zero at both ends when measuring. The force has no effect on sensitive gate, base layer and bonding layer at both ends and there is a strain transition zone between the base layer and the sensitive gate, the bonding layer and the base layer. The longer the horizontal width of bonding layer is, the thinner the thickness and the larger the shear modulus will be, and the strain transfer will be more efficient if the active zone of sensitive grid is longer. The paper is of theoretical guidance significance for the selection and paste of sensor strain gauge.