Modeling the influence of liquid environmental media on the mechanical properties of semi-crystalline plastic components using a multiscale simulation chain
Final Report Abstract
Plastics are inevitably exposed to a variety of different environmental media during their use, which can significantly influence their material properties. One example of this is the behaviour of polyamides under the influence of water. Here, the crystalline structure on the microscale and the chemical structure on the nanoscale are responsible for the decrease in stiffness on the macroscale. While the degree of crystallisation is decisive for the amount of water that is absorbed. The decrease in stiffness is due to the nanoscale and is caused by the introduction of water molecules between the hydrogen bonds of the polyamide chains, which again causes a decrease of the interaction forces. A multiscale simulation chain was developed in this project to enable these effects to be taken into account and the influence of a medium on semi-crystalline thermoplastics to be predicted. Polymer-solvent interactions were analysed on the nanoscale using atomistic simulations. Subsequently, diffusion simulations were carried out on the microscale, taking into account the degree of crystallisation, which is determined from an injection moulding simulation on the macroscale. The data obtained this way was homogenised and then subjected to mechanical stress on the macroscale. The behaviour predicted from the simulations was then compared with experimental data. Overall, using the described multi-scale simulation chain, it was possible to achieve a qualitative description of the material behaviour under the influence of media.
Publications
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Calculation of the macroscopic mechanical properties of polyamide 6.6 underwater influence using molecular dynamics simulations, hyperelastic material modeling of the amorphous fraction, and homogenization schemes. Polymers for Advanced Technologies, 34(12), 3722-3734.
Pilz, Tim; Melzer, Felix; Dahlmann, Rainer & Hopmann, Christian
