We are happy to annouce that a new article titled “Investigating fracture mechanisms of thermoplastics at the micrometre scale using large-scale MD simulations” has been published in the journal Engineering Fracture Mechanics (https://doi.org/10.1016/j.engfracmech.2026.112293). Eva Maria Richter and her co-authors Felix Weber, Maximilian Ries and Sebastian Pfaller use a novel framework that successfully upscales an established coarse-grained molecular dynamics (MD) model of a generic thermoplastic polymer. This approach enables simulations covering multiple micrometres of material using up to 30 million coarse-grained superatoms and therefore significantly exceeding previous MD limits. In our contribution, we systematically investigate the influence of boundary conditions, pre-crack length, and key chain properties (chain length, chain entanglement and bending stiffness) on crack propagation.
Our analysis reveals two major findings essential for multiscale modelling: first, crack propagation in thermoplastics is not governed by a minimal pre-crack length, but is primarily sensitive to the interplay between boundary conditions and simulation domain size. Second, we can identify and characterise an inactive zone – an obstacle region – that forms immediately between the crack tip and the developing polymer fibrils. This zone, whose existence was previously only hinted at, must be overcome for sustained crack growth, representing a key nanoscale mechanism. These micrometre scale MD simulations offer multiscale insights into failure of thermoplastics and provide the robust, high-resolution benchmark data necessary for the confident development and validation of next-generation multiscale modelling techniques for thermoplastics.