Galfenol复合悬臂梁磁机耦合建模及实验研究

发布时间：2018-06-21 11:05

本文选题：磁致伸缩 + Galfenol合金　；参考：《武汉理工大学》2015年博士论文

【摘要】：Galfenol合金是继Terfenol-D、PZT等脆性材料之后开发的一种具有磁致伸缩效应的智能材料,它具有优越的机械加工性能和良好的热稳定性,可在恶劣工况下进行工作,有力地填补了传统磁致伸缩材料与超磁致伸缩材料之间的空白,由其构成的Galfenol复合悬臂梁是一种智能型器件,在桥梁结构健康监控、车辆主动振动控制、飞机机翼驱动与控制等交通信息工程领域中具有重要的应用前景。在磁致伸缩变形过程中,Galfenol合金具有非线性、磁滞性和耦合效应等特征,而目前普遍采用的Jiles-Atherton模型、Preisach模型等方法对磁致伸缩材料进行非线性建模,无法完整描述Galfenol合金的磁致伸缩机理;同时Galfenol和外磁场,应力场之间有复杂的非线性耦合关系,怎样理解和表征这些耦合关系,是一个迫切急需解决的关键科学问题。本文对此进行了有益的尝试,在深入分析Galfenol材料建模的基础上,研究其耦合到悬臂梁中的关键建模方法,并制作样机进行实验验证,得到一些有益的结论。本文的主要研究贡献如下:1、在Galfenol材料的本征建模过程中,利用材料的磁滞特性构造其微观磁化模型,在微观模型的基础上使用统计学理论建立其宏观模型,并用数值求积公式求解宏观模型的数值解,解决了内核函数实现与积分离散化两个关键性问题,采用高斯-勒让德对积分进行求解,使用矩阵表示法实现内核函数,以保证模型的计算精度。2、在复合悬臂梁的优化设计中,通过对Galfenol复合悬臂梁的密度函数求解体积积分获得其内能函数,利用内能最小原理将悬臂梁的挠度表示成厚度比和弹性模量的函数,并对挠度进行优化设计,仿真研究表明,当厚度比较小时,挠度随基底厚度减少单调增加,当挠度达最大值后,随厚度比进一步增加,挠度开始减小,并将挠度和已有文献的实验进行对比研究。3、在复合悬臂梁的磁机耦合建模过程中,将Galfenol本征模型与悬臂梁模型进行耦合,利用虚功原理在二维条件下建立复合悬臂梁的隐式非线性动力学模型,提出一种非线性数值求解方法,将本文建立的复合悬臂梁动力学模型与现有模型进行对比研究,并通过实验进行验证,结果显示数值算法误差小,可靠程度高。4、在Galfenol复合悬臂梁的实验过程中,采用叠片结构的磁路设计以尽量抑制涡流损耗,利用有限元对样机磁路进行优化设计,外部磁场、弯曲负载及铍青铜层厚度三个参数被辨识,深入剖析复合悬臂梁的磁致伸缩机理,得出Galfenol合金在悬臂梁中受到拉伸和弯曲耦合作用的结论,可为进一步挖掘该悬臂梁的应用提供实验支持。本文采用理论建模、数字仿真与实验验证相结合的研究路线,取得研究内容与创新成果有效地解决了Galfenol合金的磁滞建模与复合悬臂梁的动力学响应等关键问题,对交通信息工程及控制领域其他智能材料复合悬臂梁的非线性建模亦有借鉴意义。
[Abstract]:Galfenol alloy is a kind of intelligent material with magnetostrictive effect, which is developed after the brittle material such as Terfenol-Dy PZT. It has excellent machining performance and good thermal stability. The gap between the traditional magnetostrictive material and the giant magnetostrictive material is filled by force. The Galfenol composite cantilever is an intelligent device, which is used to monitor the health of the bridge structure and control the active vibration of the vehicle. Aircraft wing drive and control have important applications in traffic information engineering. In the process of magnetostrictive deformation, the Galfenol alloy has the characteristics of nonlinearity, hysteresis and coupling effect. However, the Jiles-Atherton model and Preisach model are widely used to model the magnetostrictive material. The magnetostrictive mechanism of Galfenol alloy can not be fully described, and there are complex nonlinear coupling relations between Galfenol and external magnetic field. How to understand and characterize these coupling relationships is a key scientific problem that needs to be solved urgently. Based on the deep analysis of Galfenol material modeling, the key modeling method coupled to cantilever beam is studied in this paper, and a prototype is made for experimental verification, and some useful conclusions are obtained. The main contributions of this paper are as follows: in the intrinsic modeling process of Galfenol material, the microscopic magnetization model is constructed by using the hysteresis characteristics of the material, and the macroscopic model is established by using the statistical theory on the basis of the microscopic model. The numerical solution of macroscopic model is solved by numerical quadrature formula, and two key problems of kernel function realization and integral discretization are solved. Gauss-Legendre is used to solve integral and matrix representation method is used to realize kernel function. In order to ensure the accuracy of the model, in the optimization design of the composite cantilever beam, the internal energy function of the composite cantilever beam is obtained by solving the volume integral of the density function of the Galfenol composite cantilever beam. The deflection of cantilever beam is expressed as a function of thickness ratio and elastic modulus by using the principle of minimum internal energy, and the deflection is optimized. The simulation results show that the deflection increases monotonously with the decrease of substrate thickness when the thickness is small. When the deflection reaches the maximum value, the deflection begins to decrease with the increase of the thickness ratio, and the deflection is compared with the experiments in previous literatures. 3. In the process of the magneto-mechanical coupling modeling of the composite cantilever beam, The Galfenol eigenmodel is coupled with the cantilever model, and the implicit nonlinear dynamic model of the composite cantilever is established by using the virtual work principle under two-dimensional conditions, and a nonlinear numerical solution method is proposed. The dynamic model of composite cantilever beam established in this paper is compared with the existing model and verified by experiments. The results show that the error of numerical algorithm is small and the reliability is high. 4. In the course of Galfenol composite cantilever beam experiment, The magnetic circuit of laminated structure is designed to suppress the eddy current loss as far as possible. The magnetic circuit of the prototype is optimized by finite element method. The external magnetic field, the bending load and the thickness of beryllium bronze layer are identified. The magnetostrictive mechanism of the composite cantilever beam is deeply analyzed and the conclusion that Galfenol alloy is subjected to the coupling of tension and bending in the cantilever beam is obtained which can provide experimental support for further excavation of the cantilever beam. In this paper, theoretical modeling, digital simulation and experimental verification are used to solve the key problems such as hysteresis modeling of Galfenol alloy and dynamic response of composite cantilever beam. It is also useful for nonlinear modeling of other intelligent materials composite cantilever beam in traffic information engineering and control field.
【学位授予单位】：武汉理工大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TB381

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