Derive the Maxwell Model and Voight Model for polymer
viscoelastic properties with regards to Creep and...
Derive the Maxwell Model and Voight Model for polymer
viscoelastic properties with regards to Creep and Stress
Relaxation. State the practical limitations of these models in
accurately describing polymer viscoelasticity
Solutions
Expert Solution
Derivation of Maxwell Model and Kelvin-Voight Model for polymer
viscoelastic materials with detail limitations are shown below.
Choose the best option:
- Viscoelastic stress relaxation
- Viscoelastic creep
Although the viscoelastic response of a polymer can be very
complex (time-dependent stress cycling for instance), two special
loading scenarios are fairly simple to describe mathematically.
1. _______ refers to scenarios for which the stress applied to a
polymer must decay over time in order to maintain a constant
strain. Otherwise, over time, the polymer chains will slip and
slide past one another in response to a constant applied...
Derive the constitutive model for a viscoelastic model that
consists of a Voigt element (E1 for spring, and η for dashpot) in
series with a spring (E2).
Now rearrange your expression so that all of the strain terms
are on the right, and all of the stress terms are on the left. The
strain portion of your constitutive model should read E1ηϵ+ϵ˙. What
are the stress terms? In your symbolic expression, type E1 as
"E_1", E2 as "E_2", σ as...
The creep rate of a viscoelastic material is measured under a
load P at 25 °C and 100 °C, respectively. What material property
causes the strain rate measured at 100 °C to be greater than that
measured at 25 °C? According to what relationship does this
material property change with temperature?
In regards to the Injection Moulding Process, discuss which
polymer properties influence the MFI (melt flow index) and how the
individual polymers MFI is related to the various processing
parameters for injection moulding. You can use diagrams to assist
with your answers if you like.
A polymer rod is tested to determine its viscoelastic response.
The rod’s cross-section is square with the side of 5mm. The rod’s
length before loading is 500mm. A tensile force of 500N is applied
to the rod and the rod’s length under load was measured as a
function of time. Instantly after applying the load, the rod is
stretched to 508mm. After 24 and 48 hour under load, the rod’s
length was measured as 550mm and 570mm, respectively. The load...
Nanoparticles are often added to polymer matrix to enhance
various properties, the interaction with the polymer largely
determines the state of the nanoparticle in the polymer matrix.
Describe two of these state and one dispersing method that can
achieved the most desirable state.
please no hand writing