Nonlinear and time-dependent electromechanical behavior of polyvinylidene fluoride

This paper describes the results from electromechanical tests conducted on polyvinylidene fluoride (PVDF) sheets showing its nonlinear and time-dependent electromechanical behavior. Mechanical and electromechanical tests were carried out for both uniaxially stretched and biaxially stretched PVDF sheets. The tests show nonlinearity in both the stress–strain response and the time-dependent response. Electromechanical dynamic tests were conducted at various superimposed pre-stress conditions. From the dynamical electromechanical tests, it is found that both biaxially stretched and uniaxially stretched PVDF sheets exhibit pre-stress dependence of their electromechanical coefficients. In addition, an attempt has been made to model the mechanical and the electromechanical behavior using a simple three-parameter viscoelastic solid model. The model captures the trends observed in the experiments and is recommended as a useful tool for designs using these materials.