考虑应力耦合的三维磁致伸缩力传感模型研究

Three-Dimensional Model of Magnetostrictive Force Sensor Considering Stress Coupling and Experimental Research

针对普通磁致伸缩材料和压电材料脆性较大的问题,设计了一种以Galfenol合金(铁-镓合金)为敏感元件的力传感机构,可对方向交变的力载荷进行检测。建立了考虑应力耦合的传感机构三维磁-机耦合模型,采用能量均分模型(Discrete Energy-averaged Model)对合金的磁化非线性进行了描述,并通过弱解式动力学方程将磁化模型与机构的动力学模型进行耦合,达到对合金磁化过程进行完整描述的目的。模型通过Comsol Multiphysics弱解式模块求解,仿真结果表明,由于考虑了应力耦合,模型可描述合金受到磁场、应力同时作用时磁化强度的变化。以Φ8×100毫米的合金研制了传感样机,试验结果表明,传感机构可对方向交变的载荷进行检测,测得的磁化强度与仿真结果吻合较好。

Considering the brittleness of normal magnetostrictive and piezoelectric materials, a new magnetostrictive force sensor is proposed, in which Galfenol alloy is taken as the sensing element. Considering the anisotropy of Galfenol, three-dimensional magneto-mechanical coupled model is presented on the basis of electromagnetic and mechanical governing equation. The nonlinear magnetization behavior of Galfenol is described by employing the discrete energy-averaged model. The coupling of the magnetization model and the structural model is implemented with the PDE weak form equations. The model is solved by using the weak form module of Comsol Multiphysics. Simulation results show that both field and stress induced magnetization can be described by using the model. A sensing prototype is designed by using a Ф8×100 mm Galfenol rod. Experimental results show that the proposed sensing structure can be used to measure alternating load. Measurements of the magnetization have a good match with the simulations.