pure shear

Soft dielectric elastomer is able to generate an

electromechanical response in terms of reversible shape

changing, which is a muscle-like behavior. The deformation

and electromechanical stability of dielectric elastomers,

classified by their deformation modes, uniaxial extension,

equal biaxial expansion and pure shear, are investigated.

Pull-in instability occurs in equal biaxial and uniaxial modes

at a small stretch ratio, while the pure shear mode features

wrinkling instability after a large stable deformation. The

Many people puzzle over the nomenclature of the pure shear test. They rightly point out that 1) the Pure Shear test piece is loaded in tension by extending the specimen in the axial direction, and 2) a shearing deformation, by definition, involves the lateral motion of parallel planes. They wonder where is the "shear"? and what does it mean to say that the shear is "pure"?  Here, we review the origins of the terminology.