@Bev D They can be used for a wide variety of
physical property testing. One example from my automotive background is the testing of the rubber suspension components (e.g., rear suspension links, strut mounts, engine mounts, etc.) to quantify their dynamic rates and (vibration) damping coefficients.
Dynamic rate is the "stiffness" under vibration (as opposed to the static stiffness). Damping coefficient is the degree to which vibration is "damped" and converted to heat versus undamped oscillation.