Abstract
A multiscale simulation method for the determination of mechanical properties of semi-crystalline polymers is presented. First, a four-phase model of crystallization of semi-crystalline polymers is introduced, which is based on the crystallization model of Strobl. From this, a simulation on the nanoscale is derived, which models the formation of lamellae and spherulites during the cooling of the polymer by using a cellular automaton. In the solidified state, mechanical properties are assigned to the formed phases and thus the mechanical behavior of the nanoscale is determined by a finite element (FE) simulation. At this scale, simulations can only be performed up to a simulation range of a few square micrometers. Therefore, the dependence of the mechanical properties on the degree of crystallization is determined by means of homogenization. At the microscale, the cooling of the polymer is simulated by a cellular automaton according to evolution equations. In combination with the mechanical properties determined by homogenization, the mechanical behavior of a macroscopic component can be predicted.
Highlights
The mechanical properties of a semi-crystalline polymer are significantly influenced by the microstructure that is formed during cooling from the melt
At the nanoscale it was shown that with the presented four-phase model it is possible to depict the growth of the crystalline regions in the form of lamellae starting from a nucleation point
The temporal evolutions of the different phases of the semi-crystalline polymer determined from this model achieved good agreement with the experimentally determined curves
Summary
The mechanical properties of a semi-crystalline polymer are significantly influenced by the microstructure that is formed during cooling from the melt. In this paper the mechanical properties in terms of the stiffness of semi-crystalline polymers are predicted under consideration of the detailed lamellar structure within the spherulites For this purpose, structure simulations will be presented at two different scales: On the one hand, at the nanoscale, the growth of the lamellae and the formation of spherulites due to branching of the lamellae are simulated. According to Di Lorenzo and Righetti [20] the general amorphous fraction has to be divided into a mobile and a rigid fraction in order to be able to describe the structural characteristics of almost all semi-crystalline polymers— due to the fact that a perfect regular folding, as assumed by Strobl [18,19], does not exist in reality.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.