ACTIVE CONTROL OF GEOMETRICALLY NONLINEAR TRANSIENT RESPONSE OF SMART LAMINATED COMPOSITE PLATE INTEGRATED WITH AFC ACTUATOR AND PVDF SENSOR

摘要

A coupled electromechanical finite element formulation for active control of geometrically nonlinear transient response of laminated composite plate is studied. First order shear deformation theory and Von Karman type nonlinear strain displacements are used. The plate is discritised using eight noded quadratic-isoparametric elements with five mechanical degrees of freedom and one electrical degree of freedom per node. Newton-Raphson iterative method in association with Newmark time integration method is used to solve the nonlinear finite element equilibrium equation. Negative velocity feedback control algorithm is used to control the dynamic response of the smart laminated composite plate. Active fiber composite (AFC) layer poled in fiber direction acting as distributed actuator and PVDF layer poled in thickness direction acting as sensor are considered. Present study involves two types of actuator sensor arrangements. Case I: the substrate is sandwiched between AFC actuator and PVDF sensor. Case II: AFC actuator and PVDF sensor are collocated on top of the substrate. The effect of piezoelectric fiber orientation in actuator layer on vibration control for both cross ply and angle ply laminates are examined.