What is the linear viscoelastic region?
The limit of the linear viscoelastic region (abbreviated: LVE region) is first determined. The LVE region indicates the range in which the test can be carried out without destroying the structure of the sample. It is the region depicted on the left side of the diagram, i.e. the range with the lowest strain values.
What are viscoelastic properties?
In materials science and continuum mechanics, viscoelasticity is the property of materials that exhibit both viscous and elastic characteristics when undergoing deformation. Viscous materials, like water, resist shear flow and strain linearly with time when a stress is applied.
What is the main difference between a viscoelastic and linear elastic material?
Elastic behavior versus viscoelastic behavior Because viscoelastic materials have the viscosity factor, they have a strain rate dependent on time. Purely elastic materials do not dissipate energy (heat) when a load is applied, then removed; however, a viscoelastic substance does.
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 meant by Linear viscoelasticity?
Linear viscoelasticity is a theory describing the behaviour of such ideal materials. Linear viscoelasticity is a reasonable approximation to the time-dependent behaviour of polymers, and metals and ceramics at relatively low temperatures and under relatively low stress.
What do viscoelastic mean?
Being viscoelastic means that the material to some extent both behaves like a liquid and a solid material, and that it has a time-dependent strain. Download pdf: What is Viscoelasticity.
What is G in viscosity?
The G” refers to the viscous modulus, which reflects the flow of a material while it is deformed. This is viscous flow. Many real materials, including many polymers, will exhibit some elastic and some flow behavior.
How is the limit of the linear viscoelastic region determined?
The limit of the linear viscoelastic region (abbreviated: LVE region) is first determined. The LVE region indicates the range in which the test can be carried out without destroying the structure of the sample. It is the region depicted on the left side of the diagram, i.e. the range with the lowest strain values.
Which is a mechanical model of linear viscoelasticity?
Mechanical (rheological) models The word viscoelastic is derived from the words “viscous” + “elastic”, that is, a viscoelastic material exhibits both elastic and viscous behaviour. We can build up a theory of linear viscoelasticity by considering simple linear elements such as the (elastic) linear spring and the (viscous) linear dash pot2.
What do you need to know about viscoelasticity?
Demonstrate an understanding of viscoelastic material behavior including strain rate dependence, stress relaxation, creep, hysteresis and preconditioning. Communicate scientific information about why the molecular-level structure of viscoelastic materials is important in the functioning of designed materials.
When is viscoelasticity represented by a Volterra equation?
Linear viscoelasticity is when the function is separable in both creep response and load. All linear viscoelastic models can be represented by a Volterra equation connecting stress and strain :