Towards a nonlinear buckled piezoelectric beam system for enhanced electromechanical energy conversion

The present paper investigates the nonlinear dynamic electromechanical conversion capability of axially prestressed piezoelectric strips, vibrating under transverse mechanical impulsive forces. A computational structural dynamics framework is adopted, comprising a mixed-field laminate plate theory together with an eight-node coupled plate finite element, that encompass nonlinear effects due to large rotations and initial stresses. The dynamics incorporate all linear and nonlinear coupling terms between mechanical and electric fields, and emphasis is given on the presentation and analysis of nonlinear stiffness and electromechanical coupling terms that affect the electric charge and energy in the piezoelectric devices. The resultant discretized equations of motion are finally linearized and solved using the Newmark implicit time integration scheme in combination with the Newton-Raphson iterative technique. Numerical evaluation cases investigate the nonlinear vibratory response and the electromechanical energy conversion capacity of prestressed vibrating piezoelectric strips excited by transverse impulsive forces. The effect of axial preloading and transverse dynamic loading on both the nonlinear dynamic electromechanical response and electromechanical energy conversion is quantified.