Journal
POLYMER
Volume 55, Issue 23, Pages 5938-5947Publisher
ELSEVIER SCI LTD
DOI: 10.1016/j.polymer.2014.06.050
Keywords
Shape memory polymer; Stretch induced softening; Mullins effect
Categories
Funding
- AFOSR grant [FA9550-13-1-0088]
- AFRL faculty summer fellowship program
Ask authors/readers for more resources
During a cyclic tension test, many elastomeric materials exhibit an appreciable softening in their mechanical properties resulting from the previous stretch, known as the Mullins effect. This paper explores the influence of the stretch induced softening effect to the free recovery behavior of an acrylate shape memory polymer (SMP) composite by incorporating carbon black (CB) as filler materials. The observed softening effect in this SMP composite is considered to be a consequence of stretch induced alternation of filler polymer interactions inside the composite. Further experiments find that a larger prior stretch gives a larger increase in material softening, which in turn decreases the shape recovery speed. To capture the experimental observations, a multi-branch one dimensional (1D) model is applied, where the modulus in the equilibrium branch is modeled to decrease with stretching deformation following a damage-like softening function. It is found that the loss in modulus due to softening consequently reduces the driving force for recovery and thus results in a slow recovery. Parametric studies further demonstrate that the discounted shape recovery speed will finally reach a saturated level when gradually increasing the programmed strain level in a shape memory cycle. (C) 2014 Elsevier Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available