Modeling strain hardening in glassy polymers based on the microscopic mechanisms revealed by molecular dynamic simulations
Zhao W, Xiao R, Pfaller S, Steinmann P (2025)
Publication Type: Journal article
Publication year: 2025
Journal
Book Volume: 206
Pages Range: 106384
Article Number: 106384
DOI: 10.1016/j.jmps.2025.106384
Abstract
We perform molecular dynamics (MD) simulations to investigate the microscopic mechanisms underlying strain hardening in glassy polymers. The results reveal that strain hardening originates from heterogeneous local stretching within entangled segments of polymer chains. In each segment, the most extended bond, defined as the load-bearing bond, governs the response of the segment to mechanical deformation. Through averaging the stretch of these load-bearing bonds, a load-bearing deformation gradient is defined, which correlates with the macroscopic stress response through a neo-Hookean relation in the hardening regime. The extracted hardening modulus is independent of chain length, temperature, and strain rate, indicating that it may represent an intrinsic material constant. We further propose an evolution equation for the relaxation of entangled segments driven by the hardening stress based on MD observations. Through incorporating the load-bearing and entanglement relaxation mechanisms, a constitutive model is further developed with the ability to accurately capture the stress–strain relationship of glassy polymers across a broad range of temperatures, strain rates, and chain lengths. The work provides a unified microscopic theoretical framework for complex mechanical behavior of glassy polymers.
Authors with CRIS profile
Wuyang Zhao
Lehrstuhl für Technische Mechanik (LTM)
Sebastian Pfaller
Lehrstuhl für Technische Mechanik (LTM)
Paul Steinmann
Lehrstuhl für Technische Mechanik (LTM)
Related research project(s)
Configurational Mechanics of Soft Materials: Revolutionising Geometrically Nonlinear Fracture (SoftFrac)
Jan. 1, 2023 - Dec. 31, 2027
Investigating brittle-to-ductile transition in glassy polymers by multiscale modeling across atomistic and continuum scales
Feb. 1, 2025 - Jan. 31, 2027
Involved external institutions
China (CN)How to cite
APA:
Zhao, W., Xiao, R., Pfaller, S., & Steinmann, P. (2026). Modeling strain hardening in glassy polymers based on the microscopic mechanisms revealed by molecular dynamic simulations. Journal of the Mechanics and Physics of Solids, 206, 106384. https://doi.org/10.1016/j.jmps.2025.106384
MLA:
Zhao, Wuyang, et al. "Modeling strain hardening in glassy polymers based on the microscopic mechanisms revealed by molecular dynamic simulations." Journal of the Mechanics and Physics of Solids 206 (2026): 106384.
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