Before revision: Any area covered by integrating each instant of a loading and unloading cycle will then be in terms of force times length per volume, which is equivalent to energy per unit volume.
After revision: thumbnail|Energy per unit volume disapated by mechanical damping for an elastic materialAny area covered by integrating each instant of a loading and unloading cycle will then be in terms of force times length per volume, which is equivalent to energy per unit volume.