High Sensitivity Impact Force Sensor Based on Galfenol Alloy

Bo LI
2019 Journal of Mechanical Engineering  
1. 武汉理工大学智能制造与控制研究所 武汉 430063; 2. 温州大学浙江省低压电器智能技术重点实验室 温州 325035) 摘要:目前基于压电材料等的冲击力传感器由于其材料本身的脆性限制了其应用范围,Galfenol 合金具有中等磁致伸缩以及 较高机械强度,更适用于对冲击载荷的检测。提出以 Galfenol 合金(铁-镓合金)为敏感元件的磁致伸缩冲击力传感器,提出三 种不同结构的敏感元件(棒、等截面矩形梁与变截面工字梁),通过建立动力学模型对比其整体的传感性能,并采用正交设计 的方法对变截面工字梁的尺寸进行优化设计。动力学模型的对比表明,基于变截面工字梁的传感器灵敏度最高。对基于变截 面工字梁的传感器进行试验研究,并采用麦夸特法对传感器进行标定,试验结果表明该传感器可实现对冲击力准确测量,平 均误差不超过 5.73%。该传感器可实现对瞬态冲击的检测,拓宽了 Galfenol 合金的动态检测领域。冲击载荷可直接作用在传 感器的 Galfenol 合金梁上,不需要额外的保护措施,结构更简单。通过结构优化对传感器的灵敏度作了进一步的提升。
more » ... l 合金;正交设计;麦夸特法 Abstract:The present impact force sensor based on piezoelectric materials is limited in application range due to the material brittleness. Galfenol alloy is a steel like material with moderate magnetostrictive and high mechanical strength properties, which is more applicable for impact detection. A Galfenol alloy based impact force sensor is presented. Three different configurations of sensitive elements including uniform rod, rectangular beam, and un-uniform I beam, are designed. The continuous kinetic models are developed to compare the total sensing performance, and the optimal size of the un-uniform I beam is obtained by employing the orthogonal design method. The kinetic models indicate that the un-uniform I beam based sensor demonstrates optimal sensitivity compared with the other two designs. The un-uniform I beam is constructed experimentally and the senor is calibrated via a Levenberg-Marquardt fitting method. Experimental results show that the impact force can be detected accurately with a limited measurement error within 5.73 %. The proposed sensor can be used to detect instantaneous impact, which broadening the application of Galfenol alloy in dynamic force detection. The impact can be applied directly on the sensitive element with no extra protection, leading to a compact structure. The sensitivity of the sensor is further improved by structural optimization.
doi:10.3901/jme.2019.08.014 fatcat:u3urzmvinvh7liquvni3uo3o3e