Research On The Dynamics Of Composite Laminates With MFC Smart Layers

Intelligent structures can sense changes in the surrounding environment and respond appropriately to such changes.Because of this excellent performance,intelligent structures are widely used in various engineering fields.As an intelligent structure,piezoelectric material structure can effectively control its own vibration according to its own characteristics.Piezoelectric macro-fiber(MFC)is a sandwich structure composite material,in which piezoelectric ceramic fibers are embedded in resin and combined with composite electrodes.As a new type of smart piezoelectric material,compared with the traditional piezoelectric material,MFC has the characteristics of high performance,good flexibility and reliability.It has broad application prospects in structural diagnosis,detection,driving deformation and vibration control.Therefore,it is of great theoretical value and the practical application value of engineering to strengthen the research on dynamic characteristics of composite laminated structures containing smart piezoelectric material MFC.In this paper,the dynamic model of four-layer orthogonal carbon fiber reinforced composite laminates with MFC piezoelectric smart material layer is established.The free vibration of carbon fiber reinforced composite laminates and composite laminates with MFC smart piezoelectric layers,as well as the critical buckling load,nonlinear dynamics and chaotic dynamic responses of the system under in-plane loads are studied.The research contents and main achievements of this paper are as follows.(1)Based on the first-order shear deformed plate theory,a new displacement field is obtained by introducing the zigzag function term into the in-plane displacement.Considering the electromechanical coupling characteristics,the constitutive equation of composite laminates with MFC smart piezoelectric layer is obtained,and then the total potential energy,total kinetic energy and external force work of composite laminates with MFC smart material layer are obtained.Electric potential energy of MFC smart material layer.(2)According to the given new displacement field,using Rayleigh-Ritz method and Chebyshev polynomial,considering the electromechanical coupling characteristics,the natural frequencies of free vibration of carbon fiber reinforced composite laninated cantilever plate with piezoelectric macro-fiber smart material layer under two kinds of electrical boundary conditions are obtained,and the different laying modes,width-width ratio,length-width ratio and so on are discussed.The effect of MFC intelligent layer on the natural frequency of carbon fiber reinforced composite laminates under different external voltage states.(3)Based on the obtained modal modes and Lagrange equation,the nonlinear ordinary differential dynamic equation of the studied system is obtained,and the critical buckling loads of the system under linear state are obtained.The effects of width-thickness ratio,Layers of MFC and electrical voltage on the critical buckling of four kinds of composite laminates are discussed.(4)The dynamic stability of composite laminates with MFC smart layer subjected to in-plane mechanical loads was studied.The effects of static factor,dynamic factor,on-line voltage and MFC layers and positions on the unstable region of composite laminates under three fiber laying orders were analyzed.(5)The chaotic and bifurcation behaviors of three composite laminates with different stacking sequence and the system with single-layer MFC layer on the upper surface under both electrified and non-electrified conditions were analyzed.The dynamic bifurcation of composite laminates with MFC smart layer is studied.The effects of various parameters of the system on the nonlinear dynamic behavior are analyzed by phase diagrams and bifurcation diagrams.