What is the difference between viscoelasticity and Viscoplasticity?
From a rheological perspective, the primary difference between a viscoplastic and viscoelastic material is the presence of a yield stress. A viscoplastic material has a yield stress under which it will not deform, whereas a viscoelastic material will deform at any application of stress.
What is visco plastic material?
Viscoplasticity is a theory in continuum mechanics that describes the rate-dependent inelastic behavior of solids. Rate-dependence in this context means that the deformation of the material depends on the rate at which loads are applied.
What is viscoelasticity as a material property?
Viscoelasticity is the property of materials that exhibit both viscous and elastic characteristics when undergoing deformation. Synthetic polymers, wood, and human tissue, as well as metals at high temperature, display significant viscoelastic effects.
What is viscoplastic behavior?
Viscoelastic or viscoplastic behavior of a material shows itself in various ways, such as creep under constant load, time-dependent recovery of deformation followed by load removal, stress relaxation under constant deformation, and time-dependent creep rupture.
Why are polymers viscoelastic?
One important characteristics of polymeric materials is their viscoelastic behavior. This means that polymer is elastic because after a strain due to the application of a stress, it is capable to recovers. On the other hand, polymers are viscous because their capability to creep after the strain.
What is Johnson Cook model?
The Johnson-Cook model is a plasticity model that is based on Mises plasticity with closed-form analytical equations specifying the hardening behavior and the strain-rate dependence of the yield stress.
What is Elasto plastic?
Definition of elastoplastic (Entry 1 of 2) : a substance having both elastic and plastic properties : a rubberlike plastic.
Are plastics viscoelastic?
The primary property that makes most plastics so attractive over other materials is viscoelasticity. This gives plastic the ability to absorb energy, flex and spring back without cracking.
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.
Is glass a viscoelastic material?
Glass, recently redefined as a nonequilibrium, noncrystalline condensed state of matter,1 contains a glass transition, the region at which it strongly exhibits viscoelastic behaviors.
Is concrete a viscoelastic material?
Hence, cement concrete is a viscoelastic material.
What is transient creep?
Transient creep of concrete is defined as the creep that occurs during first time heating at a constant rate under load. The specific definitions for non-drying and drying concrete are given in Sections 3.3 and 3.4, respectively.
Why is rubber viscoelastic?
They are viscoelastic by virtue of their time-dependent mechanical response, which reflects the sluggish configurational changes of the molecules. Upon being crosslinked sufficiently, a chemical molecular network (rubber or elastomer) is formed that transforms the polymer into a viscoelastic solid, which does not flow.
How does slip occur?
Slip occurs by the passage of dislocations on close packed planes which are planes containing the greatest number of atoms per area and in close-packed directions (most atoms per length). Close-packed planes are known as slip or glide planes.