A physics-informed multi-agents model to predict thermo-oxidative/hydrolytic aging of elastomers

• Published in: International journal of mechanical sciences 2022-06, Vol.223 (C), p.107236, Article 107236
• Main Authors: Ghaderi, Aref, Morovati, Vahid, Chen, Yang, Dargazany, Roozbeh
• Format: Article
• Language: English
• Subjects: Data-driven constitutive modeling; Hydrolytic aging; Multi-agent system; Neural networks; Thermo-oxidative aging
• ISSN: 0020-7403; 1879-2162
• DOI: 10.1016/j.ijmecsci.2022.107236

This paper introduces a novel physics-informed multi-agents constitutive model to propose prediction in quasi-static constitutive behavior of cross-linked elastomer and the loss of mechanical performance during environmental aging. The presented model is used to simulate the effect of single-mechanism chemical aging (i.e. thermal-inducedor hydrolytic aging) on the behavior of the material in this hybrid framework. Those environmental single-mechanism damages change the polymer matrix over time due to massive chain scission, chain formations, and changing the arrangement of molecules in the polymer matrix. We propose a data-driven super-constrained machine-learned engine to represent damage in the polymer matrix and capture the changes in material behavior, including its inelastic features such as Mullins effect and permanent set in the course of aging. We have simplified the 3D stress–strain tensor mapping problem into a small number of super-constrained 1D mapping problems by means of a sequential order reduction. An assembly of multiple replicated conditional neural-network learning-agents (L-agents) is trained to systematically simplify the high-dimensional mapping problem into multiple 1D problems, each represented by a different type of agent. Our hybrid framework is designed to capture the effect of deformation history, aging time, and aging temperature. The model is validated with respect to a comprehensive set of experiments specifically designed to benchmark model capabilities and also against available data in the literature. Thermodynamic consistency and frame independency have been verified. Besides acceptable predictive abilities, a significant reduction of computational cost to predict behavior at multiple states of deformation is the most significant feature of this model. [Display omitted] •Hybrid framework on mechanical behavior of elastomers during environmental aging.•A physics-based model coupled into a machine learning process.•The proposed model infuses knowledge to reduce the need for data.•Thermodynamic consistency and frame independency will be verified.