Damage reduction of on-board structures using piezoelectric components and active modal control—Application to a printed circuit board

The reliability of Printed Circuit Boards (PCB) is critical for on-board electronic systems, particularly when subjected to severe stress conditions. This paper presents an approach to reduce the vibration damage in PCBs that can be extended to the majority of on-board structures subjected to damage. Vibration damage highly depends on mode shapes under large band excitations. A solution to reduce vibration from the most damaging modes is to use active modal control for targeting efficiently control energy on most damaging modes. Following this modal-damage strategy, the most damaging modes are determined using a damage analysis based on an initial detailed Finite Element Model (FEM) of the PCB. The control is then designed using only a few piezoelectric components located so as to be essentially effective on these modes. The location algorithm of these active components uses a second simplified FEM including the damage simulation results. Finally, a classical Linear Quadratic Gaussian algorithm is used to determine the modal controller-observer gains. The effectiveness of the proposed method for PCBs is then examined through experiments with different high-level excitations. The proposed control is finally validated by a new damage analysis of the controlled PCB to estimate damage reduction. The study realized on an actual PCB shows that the modal approach permits to link damage estimation, optimal placement of actuator, optimal control and minimization of control energy. Moreover, the predictions of damage reduction and of actuation energy are in good agreement with the experimental results, which shows that the modal description of on-board smart structure, in particular PCB, is the key point in damage reduction with vibration active control.