Nonlinear fracture mechanics analysis of nano-scale piezoelectric double cantilever beam specimens with surface effect

• A non-linear fracture mechanics analysis model for DCB fracture specimens is developed.
• The model incorporates surface effect and the finite deformation theory.
• Geometrically nonlinear deformation decreases the prediction of energy release rate.
• The effect of surface stress on energy release rate is significant for thinner beams.

A fracture mechanics analysis model for the piezoelectric double cantilever beam (DCB) fracture specimens is developed. The model incorporates residual surface stress, surface elasticity and surface piezoelectricity and considers the finite deformation theory. Based on Timoshenko beam theory, the governing equation is derived and solved numerical. Consideration of geometrically nonlinear deformation will significantly decrease the prediction of energy release rate. The effects of residual surface stress and surface elasticity on the energy release rate is more significant for a thinner beam. The influence of surface residual stress on the energy release rate depends on the length to thickness ratio of the DCB. For open-circuit boundary condition, the applied voltage and surface piezoelectricity can affect the energy release rate, and the effect of surface piezoelectricity is more obvious for a thinner beam. However, for short-circuit boundary condition the surface piezoelectricity cannot affect the energy release rate.