Shape memory polymer – Mechanics of Polymers

VUMAT for finite strain viscoelasticity

July 30, 2026 by admin

Together with my student Damien Ollion, we have converted the finite-strain viscoelastic UMAT originally developed with Florian Gouhier into a VUMAT for Abaqus/Explicit. The implementation reproduces the constitutive model of Reese and Govindjee (1998) for a generalized Maxwell model and includes the following features: A comprehensive How-to-use.pdf document is provided. It presents the constitutive equations, illustrates the...

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Abaqus finite strain Polymer Shape memory polymer soft polymers viscoelasticity

Shape memory property of amorphous polymer networks. Experimental characterization (2)

December 1, 2016 by admin

In a previous post, I have presented some of our results obtained during stress-free shape memory recovery of amorphous polymer networks submitted to large deformation torsion tests. These tests introduce large deformation but moderate strain. In order to provide a rather complete set of data on the strain recovery and `stress recovery’ for amorphous polymers, including large strain, uniaxial...

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Shape memory polymer strain recovery Stress recovery temperature viscoelasticity

Shape memory property of amorphous polymer networks. Mechanical model

December 1, 2016 by admin

The shape memory property of amorphous polymer networks is the result of two intrinsic properties of these materials: 1) The viscoelasticity and 2) the time-temperature superposition property. This can be proven by characterizing the material linear viscoelasticity and time-temperature superposition with DMA (dynamic mechanical analysis) tests and by introducing these properties in a TRS (thermo-theologically...

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Shape memory polymer Time-temperature superposition viscoelasticity

Shape memory property of amorphous polymer networks. Experimental characterization (1)

July 28, 2016 by admin

I started working on the shape memory property of polymers at CU Boulder thanks to Professor Ken Gall who introduced me to the topic. Focusing on amorphous polymer networks, with several co-workers we have been working on the characterization and the modeling of this property. This post is about the experimental characterization of the...

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Shape memory polymer strain recovery torsion viscoelasticity