Response of laminated adaptive composite beams with viscoelastic interfaces

The time-dependent behavior of a simply supported laminated beam bonded with two piezoelectric layers (one is bonded onto the uppermost surface of the laminated elastic beam, another onto the lowermost surface), which may be sensor or actuator, is studied using the state-space method. The Kelvin–Voigt viscoelastic constitutive relation of interfaces is introduced to model the creep behavior of bonding adhesives. The response for a laminated beam with viscous interfaces is also investigated as a particular case of the present model. Since the behavior of this smart structure under static loading is time-dependent, the power series expansion technique is adopted to approximate the variations of variable fields with time. It is shown that the function of actuator or sensor will be counteracted partly by the effect of imperfect interfaces with time elapsing. The study should open a door for the failure analysis in health monitoring of engineering structures when bonded piezoelectric sensors and actuators are used.