Distributed Sensing of Static and Dynamic Fracture in Self-Sensing Piezoelectric Composite: Finite Element Simulation

Distributed sensing of static and dynamic fracture under mode-I and mode-II delamination in smart laminated composite with embedded piezoelectric sensor patches are studied. An isoparametric 4-node 3 DOF/node quadrilateral plane stress Finite Element (FE) with one active DOF/node is formulated. A consistent formulation is carried out from the coupled electro-mechanical equations of motion. The crack-tip energy release rate in the form of a generalized Energy Domain Integral (EDI) for static and dynamic fracture is implemented in the FE code to simulate the distributed sensing behavior of the embedded piezoelectric patches. Correlations between the sensor signals with the EDI under incremental delamination growth in a graphite-epoxy Double Cantilever Beam (DCB) specimen with three piezoelectric patches ahead of the delamination tip are made. The study shows various important features for sensing the incremental delamination growth, which can be used in future designs of self-sensing piezoelectric composite structures and on-line health monitoring systems.