Font Size: a A A

The Magnetomechanical Coupling Modeling And Experiment Of Galfenol Composite Beam

Posted on:2016-06-16Degree:DoctorType:Dissertation
Country:ChinaCandidate:Q H CaoFull Text:PDF
GTID:1311330476955896Subject:Traffic Information Engineering & Control
Abstract/Summary:PDF Full Text Request
Galfenol alloy is a new smart material with magnetostrictive effect after brittle material such as PZT, Terfenol-D. Mechanical strength ensures that it can be loaded this bending moment and tensile loads safely. There are excellent machining performance and good thermal stability in Galfenol alloy, The development of this alloy has effectively filed up the gap between traditional magnetostrictive materials and giant magnetostrictive materials. Galfenol composite beam, which is made up of Galfenol alloy, has a broad prosepect in traffic information engineering field, such as the bridge structural health monitoring, vehicle active vibration control, the drive and control on aircraft wing.In the process of magnetostrictive deformation, Galfenol alloy has the characteristics of nonlinearity, hysteresis and coupling effect, the current widely used nonlinear modeling methods, including Jiles-Atherton model and the Preisach model, can not completely description magnetostrictive mechanism of the Galfenol alloy; The nonlinear coupling modeling of Galfenol alloy has been connected with field vector, stress tensor and eddy current. It is a key scientific problems needed to resolve urgently how to understand and characterize the coupling relationship. The paper has carried on the beneficial attempt, the constitutive model has been coupled with the structural beam model on the basis of thorough analysis of Galfenol modeling, the main research contributions are as follows:1. In the process of Galfenol intrinsic modeling, the material hysteresis characteristic is used to establish the microscopic model, statistical theory is adopted to establish the macro model on the basis of the microscopic model. The numerical solution of the macro model is solved by quadrature formula, two key questions(the kernel function and integral discretization) is solved, It states that the method in which the approximately Gauss-Legendre integral method is used to integral discretization and matrix representation is used to implement integral kernel function not only increases computational efficiency but also guarantee computational precision.2. Internal energy function is acquired through solving the volume integral by the density function of Galfenol composite cantilever. the deflection of beam is expressed as a function of thickness ratio and elastic modulus with the internal energy minimum principle and is optimized, simulation results show as follows: when the thickness ratio is small, the deflection increases monotonously with the basal thickness reduction, when the deflection reaches the maximum, with the further increase of thickness ratio, deflection began to decrease.3. In the process of modeling of Galfenol composite cantilever, the Galfenol intrinsic model is coupled with the cantilever beam model, the implicit nonlinear dynamic model is established by the virtual work principle, a kind of nonlinear numerical method is put forward, the composite cantilever beam dynamics model is compared with the existing model to verify the feasibility of modeling method, and experiment is done to verified dynamics model, the results show error of numerical algorithm is small and dependability of numerical algorithm is high.4. In the process of experiment of Galfenol composite cantilever, the laminated structure of magnetic circuit is designed to try to suppress the eddy current loss, magnetic circuit is optimized by the finite element, three parameters(magnetic field, bending load and thickness of beryllium bronze) have been identified, Galfenol alloy in composite cantilever is deeply analyzed by the coupling of the tensile force and bend, which provide the experimental support of application in the field of traffic information engineering and control.The research route of combining the theory modeling, numerical simulation with the experiment is used in this paper, hysteresis modeling of Galfenol and dynamic response of the composite beam effectively solves by the research content and innovation achievements. It is significant to establish nonlinear modeling of other intelligent composite cantilever beam in traffic information engineering and control.
Keywords/Search Tags:Magnetostriction, Galfenol alloy, Composite cantilever beam, Magnetomechanical modeling, Experiment
PDF Full Text Request
Related items