|
A novel concept for sound generation using buckled dielectric (DE) elastomer membranes was proposed recently, which relies on buckling induced by a DC voltage, superimposed by an AC signal voltage to force vibration. To accurately describe the large amplitude vibrations of buckled, viscoelastic structures at frequencies in the audio spectrum, complex theories are required in general. In this work, a compact differential equation is derived, which rests on some simplifications to reduce the complexity of the problem. To assess its validity, several devices of different diameters and thicknesses are experimentally investigated and compared to the model. As expected, the model loses accuracy with increasing relative thickness, which is in line with other studies in the field. For moderately thick plates the stiffness is underestimated due to neglected shear effects. But, for relatively thin membranes the model provides an efficient tool to predict the post-buckling behavior of DE membranes and will help develop lightweight and small loudspeakers.
|
