Difference between revisions of "Electrical breakdown and ultrahigh electrical energy density in poly(vinylidene fluoride-hexafluoropropylene) copolymer"

The difference behind the two model lies on the consideration of potential plastic deformation. The authors claim that Stark-Garton model overestimates the breakdown strength, because it mistakenly assumes the deformation is purely elastic, which follow the elastic stress-strain relastionship $Yln(d_0/d)$ where Y represents the Young's modulus, $ln(d_0/d)$ refers to the true stain. What's worse, the model simply ignores the potential plastic deformation, leading the failure to occur below the critical stress. To improve the model,the authors gave up the elastic model and used the power law relation instead. It goes like $\sigma=Ke^N=K(log\frac{d_0}{d})^N$. When N=1, we have K equal Y which is the linear elastic relation. By contrast, N=0, an ideal plasticity occurs. Based on this new model, the predicted result is improved, reflected in the better fitting result of the experimental curves, as showed in the figure 3