Non-linear vibration analysis of smart composite structures with discrete delamination using a refined layerwise theory

A non-linear vibration analysis procedure has been developed to investigate the dynamic response of composite laminates with embedded and/or surface bonded piezoelectric sensors and multiple finite/discrete delaminations. The objective is to accurately predict the sensor output in the time domain. A recently developed refined layerwise composite theory is used to develop the piezoelectric-mechanical model. A two-way coupled electro-mechanical formulation is used to derive the equations of motion. An adaptive non-linear transient implicit algorithm is used to generate the voltage time history, which is useful in characterizing the presence of delamination. The contact problem of delaminated interfacial surfaces is modelled in terms of fictitious linear springs to provide an accurate description of the transient behavior. The accuracy of the model is validated through comparison with experimental results. The validity of low frequency vibration analysis in detection of delamination(s) from in-situ sensor outputs is also established. It is anticipated that the developed framework will be a useful tool in structural health monitoring studies.