An experimental investigation of a passive stand-off layer damping treatment applied to an Euler-Bernoulli beam

Passive stand-off layer (PSOL) damping treatments are presently being implemented in many aerospace and defense designs. In a PSOL damping treatment, a stand-off or spacer layer is added to a conventional passive constrained layer (PCL) damping treatment. The addition of this stand-off layer increases the distance of the viscoelastic and constraining layers from the neutral axis of the vibrating structure. This is thought to enhance the damping by increasing the shear angle of the viscoelastic layer. In this experimental study, a PSOL damping treatment was applied to an Euler-Bernoulli beam. The frequency response of the treated PSOL beam was then compared with a conventionally treated PCL beam of similar dimensions and materials. Previous theoretical studies indicated that PSOL treatments provided greater damping than similarly sized conventional PCL treatments. This study verified experimentally that the beam treated with PSOL had greater damping of the first four modes than a similarly sized beam treated with PCL.