TY  - THES
T1  - Modelling and Computation of Polymer Curing
A1  - Hossain,Mokarram
Y1  - 2011/06/15
N2  - Motivated by the phenomenological concept of stiffness gain due to crosslinking during curing process of highly cross-linked polymers, i.e. thermosets, a one-dimensional curing equation has been developed which is later extended to the three-dimensional form suitable for the small strain deformation. The small strain three-dimensional elastic model is then extended to viscoelastic case. For the volume shrinkage, the time-dependent volume shrinkage formulations of Kiasat are incorporated in the newly developed model. The simplicity of this model is that, it requires only two time evolving material parameters, i.e. the shear modulus and the relaxation time. As polymeric materials are highly deformable, so finite strain model is immensely required. Inspired by the small-strain formulation, a thermodynamically consistent finite strain framework for the curing modelling is also proposed in this contribution. One of the main advantages of the developed framework is that any energy function, whether it is phenomenologically- or micromechanically-motivated, can be inserted into it. Two approaches, e.g. either using a pre-defined shrinkage function as in small strain model or using the multiplicative decomposition of the deformation gradient, have been embedded into the constitutive relation to incorporate the shrinkage effects. We ignore thermal effects for simplicity and take only the mechanical and the volume changes using a multiplicative decomposition of the deformation gradient. Several numerical examples (homogeneous and inhomogeneous) demonstrate that the developed approaches are suitable to correctly reproduce the relevant mechanical phenomena observable in polymers during curing process.
KW  - Polymeren, Aushärtung, Modellierung
CY  - Erlangen
PB  - Universitätsbibliothek der Universität Erlangen-Nürnberg
AD  - Universitätsstraße. 4, 91054 Erlangen
L2  - http://www.opus.ub.uni-erlangen.de/opus/volltexte/2011/2637
ER  -