What is viscoelasticity of polymer?
Materials that exhibit both viscous and elastic characteristics when deformed under stress are known to be viscoelastic. And this would include any polymeric material—from butter to bicycle helmets. (Yes, butter, a lipid, consists of long chains of identical, repeating molecules known as monomers, i.e., a polymer.
What is viscoelasticity example?
Typical examples of viscoelastic materials are spaghetti, shag (tobacco), a pile of worms moving through each other and (of course) polymers. Polymers are always viscoelastic because they consist out of long molecules which can be entangled with their neighbors.
What is viscoelasticity explain in brief?
In materials science and continuum mechanics, viscoelasticity is the property of materials that exhibit both viscous and elastic characteristics when undergoing deformation. Elastic materials strain when stretched and immediately return to their original state once the stress is removed.
What is viscous relaxation?
These morphological characteristics can be explained by viscous relaxation of topography on an icy crust in which the viscosity is uniform or decreases with depth. Under these conditions, large craters relax more rapidly than small craters, therefore explaining a possible underabundance of large craters.
How is viscoelasticity measured?
In industries such as biomaterials, viscoelasticity is often measured by applying a sinusoidal force, calculating the resulting strain response and determining the elastic-spring-like storage modulus and the flow-like loss modulus. Such dynamic mechanical analysis can be performed as a bench test or deployed in-situ.
What is Linear viscoelasticity?
Linear viscoelasticity is an extension of linear elasticity and hyperelasticity that enables predictions of time-dependence and viscoelastic flow. From: Fluoropolymers Applications in the Chemical Processing Industries, 2005.
What is viscoelasticity explain rate dependent and time dependent properties of connective tissue?
When forces are applied to viscous materials, the tissues exhibit time dependent and rate-dependent properties. All connective tissues are viscoelastic materials Their behavior is time and history dependent and is a combination of the properties of elasticity and viscosity.
What is viscoelasticity of muscle?
A MATERIAL’S ABILITY TO DAMP MOVEMENT BY BECOMING STIFFER AT HIGHER RATES OF ELONGATION.
What is viscoplastic material?
Viscoplasticity is a theory in continuum mechanics that describes the rate-dependent inelastic behavior of solids. The inelastic behavior that is the subject of viscoplasticity is plastic deformation which means that the material undergoes unrecoverable deformations when a load level is reached.
What is polymer relaxation time?
The relaxation time is the time associated with large scale motion (or changes) in the structure of the polymer, we denote this time scale by λ.The microscopic timescale should be compared with the macroscopic flow time scales. The macroscopic time scales arises from two origins.
How is stress relaxation calculated?
The relationship between E and η is given by the equation τ = η / E where τ is known as the relaxation time for a mechanical system exposed to a controlled stress.
