Experimental Study on the Electro‐Mechanically Coupled Biaxial Cyclic Deformation of Dielectric Elastomer at Different Temperatures

ABSTRACT The electro‐mechanically coupled biaxial cyclic tests of VHB4910 dielectric elastomer were conducted at different temperatures, including equi‐biaxial and nonequi‐biaxial tests for the proportional and nonproportional loading paths, to investigate the evolution characteristics and temperature dependence of biaxial cyclic deformation of the elastomer. The results show that VHB4910 dielectric elastomer exhibits obvious cyclic softening and remarkable ratchetting, which are further dependent on the test temperature and applied loading level/loading rate, and display obvious electro‐mechanically coupled characteristics under biaxial cyclic loading conditions. In comparison with the pure‐shear cyclic tests, the equi‐biaxial cyclic tests of the elastomer show more pronounced strain hardening and stronger electro‐mechanically coupled properties; however, in the nonequi‐biaxial cyclic tests, the electro‐mechanically coupled deformation of the elastomer exhibits a strong interaction between the responses in the two loading directions and displays different evolution features for the proportional and nonproportional loading paths, respectively, which also depend on the test temperature and applied loading rate. This work offers solid experimental support for the establishment of a temperature‐dependent electro‐mechanically coupled biaxial cyclic constitutive model of dielectric elastomers in future research.