Experimental Study Of Electromechanical Coupling Properties Of Dielectric Elastomer

Dieletric elastomer(DE) can exhibit over100%strain when subjected to a high electric field, with the advantages of light weight, fast response and high energy density. The device application of DE requires further study on the performance of DE materials. Based on this purpose, We carry out experiments to study electromechanical performance and fracture failure under mechanical and electrical fields of DE.First, Experiments on DE membrane under mechanical and electrical loadings obtain the stress-strain curves. The results indicate that the DE membranes possess significant rate dependent properties and the applied electric field will lead to the decreasement of tensile force. We adopt a rheological model based on thermodynamic inequality considering energy dissipation to derive governing equations. The results predicted by the above model agree well with those obtained by the experimental method.Second, the charging current is limited while voltages are applied on DE. When the output current reaches permitted value, there will be a turning point on the stress-strain curve. Experimental results can be well explained by electromechanical coupling model under limited charging current.Third, a multi-axial tensile machine is designed, and the loading sectors can be easily assembled and disassembled. This machine can be used to study mechanical properties of the soft materials.Finally, the crack propagations of DE subjected to electric field are studied. The video analysis software can record the crack propagation speed, and the critical tensile force before crack propagation is obtained. Furthermore, a relay circuit system is designed to achieve automatic crack arrested when crack propagates to a certain length.