Thermal Buckling And Free Vibration Analysis Of Piezoelectric Fiber Composite Beams

Piezoelectric fiber composites(PFCs) as a new piezoelectric material, compared with the conventional piezoelectric materials, exhibit good toughness, light weight, orthotropic, outstanding designability and broad prospects for development, etc. It has been widespread concern and research. The beam structure as a common mechanical and engineering components, has been one of the mechanics fundamental research disciplines. In this paper, one-dimensional model of piezoelectric fiber composite slim beam is studied, mainly to do the following three aspects.Firstly, based on Euler-Bernoulli beam theory, the geometrically nonlinear theory for axially extensible beams, using relevant theoretical knowledge of composite materials, establish large elastic deformation governing equations for a piezoelectric fiber composite beams under the uniform temperature field and electric field.Secondly, the shooting method is used to numerically solve the more strongly nonlinear boundary value problems of ordinary differential equations with multiple unknowns. The stability of the beams are analyzed respectively under three kinds of boundary conditions, fixed at both ends, pined at both ends and pined at one end, the other end fixed. Under thermal load, the buckling equilibrium configuration of the beam with different piezoelectric fiber volume fraction and the electric field intensity effect is given. The effect of the piezoelectric fiber volume fraction, and the electric field intensity influence on the critical temperatures and the post-buckled configurations of beams are analyzed and discussed. Results make us understand and know the characteristics of the piezoelectric composite materials.Finally, based on establishing the linear governing equations of the free vibrations of piezoelectric fiber composite beams in the vicinity of the thermal post-buckled configuration, the shooting method is used to solve small linear vibration in the vicinity of the thermal post-buckled slender piezoelectric fiber composites beams, boundary conditions of which are symmetric restraint. Characteristic curves of the first to three-order natural frequencies changing with the temperature rise are given, while thermal post-bucked piezoelectric fiber composite beams are constrained symmetrically. The influence of piezoelectric fiber volume fraction and electric field intensity on the each frequency of pre-bucked and thermal post-bucked beams are analyzed.