Elastic damping hysteresis

The above perspectives are natural consequences of both the hydrophobic and the elastic consilient mechanisms as applied to the structural data on the myosin II motor. Here we briefly explore the elastic element. An ideal elastomer exhibits exactly reversible stress-strain curves with complete recovery on relaxation of the energy of deformation. On the other hand, an elastomer that exhibits hysteresis does not recover all of the energy on relaxation that was expended on deformation. Accordingly, efficient muscle contraction should involve the deformation of near-ideal elastic segments to utilize more efficiently the energy expended in driving contraction. The mechanism of elasticity that can provide such near-ideal elasticity is the damping of internal chain dynamics on extension. 

To determine the values of material characteristics, the stress and extension signals are plotted against each other. Damping (mechanical loss) in a material causes a phase shift between strain and stress. When the two signals are superimposed, a hysteresis diagram is obtained on which four different characteristic quantities can be defined stresses, strains, elastic moduli, and mechanical losses. 

In the contact area between part and counter part elementary friction and wear mechanisms such as adhesion, abrasion, surface fatigue, deformation, elastic hysteresis and damping, tribochemical reactions etc. may occur. These mechanisms are overlapping in the temporal and spatial undetectable real material contact area. In addition highly formulated lubricants, which are mainly used with highly stressed engine elements, exert influence on tribochemical reactions inside and outside of the tribological contact. ... 

If the output data is recorded on a X-Y recorder or an oscilloscope, a hysteresis loop as shown in Fig. lOB is obtained. The area of the loop is proportional to the damping or energy dissipation of the system. The loop is a circle for the Newtonian fluid, a line for a Hookian body, and an ellipse for a viscoelastic body. The values for , ", and sin 6 for an elastic body can be calculated from the hysteresis ellipse using... 

Viscoelasticity is a phenomenon observed in most of the polymers since they possess elastic and viscous characteristics when deformed. The properties such as creep, stress relaxation, mechanical damping, vibration absorption and hysteresis are included in viscoelasticity. If a material shows linear variation of strain upon the application of stress on it, its behavior is said to be linear viscoelastic. Elastomers and soft biological tissues undergo large deformations and exhibit time dependent stress strain behavior and are nonlinear viscoelastic materials. The non-linear viscoelastic properties of solid polymers are often based on creep and stress-... 

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