Analysis For Bifurcation Of Carbon/Epoxy Composite Materials Subjected To Parametrical Excitation

In recent years, anisotropic laminated composite materials have been remarkable-increasingly used as structural elements. The development is due to the use of the attractive properties of composite materials, such as their high strength-to-weight and stiffness-to-weight ratios, good anti-fatigue performance, as well as anisotropy, etc. All the properties can be adjusted by changing the fiber orientation and sequence of laying floor. Therefore, laminated composite materials are effectively utilized to many industrial departments, such as aircrafts, missiles, underwater submarines, shipbuilding, and automobiles, etc., and housing construction. Composite materials are often used to make thin-walled light structures, e.g., thin plates. However, thin plates are very flexible and prone to cause violent vibration, which will consequently result in increasingly prominent problems of nonlinear dynamics. Hence, it is theoretically and practically important to study the nonlinear dynamics of the composite laminated plate.Rectangular anisotropic composite laminated plates with symmetrically and anti-symmetrically cross-by T300/5208 carbon/epoxy reinforced fiber in practical engineering are investigated in this paper. A two-degree-of-freedom nonlinear vibration system with parametrical excitation is used as a mechanical model of a plate, and nonlinear dynamic characteristics of the system are analyzed. The main research work and conclusions are summarized as follows:Firstly, mechanical properties of the composite laminated plate are introduced, and then, numerical simulation method is used to analyze the dynamic model of composite laminated plates with anti-symmetrically and symmetrically cross-by reinforced T300/5208 carbon/epoxy fiber through MATLAB and MAPLE, etc. Effects of the exciting force N_t and cross-by ways on the dynamical characteristics of the system are analyzed. Regularities of change on the qualitative and quantitative aspects for the first and second mode of the two-degree-of-freedom model are compared. Furthermore, periodic solutions, bifurcation and chaotic motion of the system and the route of entering into chaotic regime are analyzed.Secondly, trends of dynamic characteristics of the system due to changes of system parameters N_t under different initial value of the exciting force No, as well as influences of changes of the initial value of the exciting force N₀ and dissipative damping coefficient η...