What is a viscoplastic material?
Viscoplastic materials are polymer substances that show both viscous and plastic properties during the deformation of the material. This property is named as viscoplasticity. It is a rate-dependent inelastic behaviour of solids.
What is Elasto viscoplastic?
Elastoviscoplastic hardening solid An elastic-viscoplastic material with strain hardening is described by equations similar to those for an elastic-viscoplastic material with perfect plasticity. However, in this case the stress depends both on the plastic strain rate and on the plastic strain itself.
What is viscoplastic Behaviour?
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.
What is rate-dependent plasticity?
Rate-dependent plasticity describes the flow rule of materials, which depends on time. The deformation of materials is now assumed to develop as a function of the strain rate (or time). An important class of applications of this theory is high temperature creep.
What is the difference between viscoelastic and viscoplastic?
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 causes viscoelasticity?
Viscoelasticity is caused by temporary connections between fiber-like particles. Polymers always show a viscoelastic behavior because they consist of long molecules able to make temporary connections with their neighbors.
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 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 plastically deformed?
Plastic deformation is the permanent distortion that occurs when a material is subjected to tensile, compressive, bending, or torsion stresses that exceed its yield strength and cause it to elongate, compress, buckle, bend, or twist.
How do you test for viscoelasticity?
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 the difference between elasticity and viscoelasticity?
As nouns the difference between elasticity and viscoelasticity. is that elasticity is (physics) the property by virtue of which a material deformed under the load can regain its original dimensions when unloaded while viscoelasticity is (physics) the property of a material that is both viscous and elastic.
Why is Johnson-Cook model used?
Johnson–Cook (JC) constitutive model is a phenomenological flow stress model based on working conditions sheet temperature, strain induced, and punch strain-rate. The JC model is widely used for various varieties of materials over different ranges of strain-rate and temperatures.