Speaker
Description
Simulating fracture and especially the fracture of thermoplastics still proves to be difficult. It yet remains unclear what exactly happens at a molecular and atomistic level when thermoplastics fail, which is rooted in the multiscale nature of the problem. Before profound multiscale simulations based on the “Capriccio” method as a multiscale domain-decomposition approach can be set up, appropriate preparation is in order. Therefore, two pure MD models of a general thermoplastic polymer (GTP) are investigated. The first focuses on the model size and captures up to 30 million superatoms. By varying material parameters and pre-crack sizes, the respective influences could be investigated. Furthermore, questions regarding the size of the process zone and the K-determined field could be answered while interesting hypotheses in terms of the crack propagation in thermoplastics could be derived. In the second model, a “Capriccio light” approach was introduced that operates fully in MD but mimics a full multiscale “Capriccio“ simulation. With this cheaper and more flexible model, the relevant influences of parameters that only appear in multiscale simulations, such as the influence of multiscale boundary conditions or the size of MD and FE regions, could be investigated leading to a better understanding of the problem at hand.
