20.500.12556/RUL-176207 Experimental and analytical framework for predicting nonlinear viscoelastic–viscoplastic behavior of polymers The present research addresses the modeling of viscoelastic–viscoplastic behavior of polymers with a theoretical expansion of Schapery’s nonlinear viscoelastic model by incorporating two components of irrecoverable processes, displaying material flow and viscoplastic behavior (structure- and load-related irrecoverable process). The theory is accompanied by an experimental and analytical framework for identifying model parameters. Introduced multi-scale analysis allows evaluation of pure linear and nonlinear viscoelastic, as well as viscoplastic behavior, enabling the study of their contribution to overall material response. Model performance was examined with creep recovery tests on two versa- tile and well-established thermoplastic polymers with different morphological structures: amorphous ABS exhibiting notable flow and semi-crystalline POM, where flow may be neglected. Results show extremely accurate predictions and exceptional agreement with experimental data, as the error was found to be less than 5% ranging from infinitesimally small to relatively high loading magnitudes (from 0.1 to 15 MPa of shear stress) at 70 ◦C (maximum operating temperature). Notably, viscoplastic strains were detected even within linear viscoelastic domain, suggesting that these effects are not related to yield phenomena (associated with progressive/damaging mechanisms), but rather provide an explanation for the material’s inability to fully recover. With its predictive capability and adaptability, the model demonstrates to be a powerful tool for capturing realistic material responses not only for the considered but also applicable to other molecular systems. polymers linear viscoelastic behavior nonlinear viscoelastic behavior viscoplastic behavior Schapery’s nonlinear model polimeri linearno viskoelastično vedenje nelinearno viskoelastično vedenje viskoplastično vedenje Schapery’jev nelinearni model true false true Angleški jezik Slovenski jezik Članek v reviji 2025-11-25 12:21:20 2025-11-25 12:21:26 2025-12-19 03:51:38 0000-00-00 00:00:00 2025 0 0 22 str. issue 23, art. 3095 Vol. 17 2025 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 544.6.018.47-036.5 2073-4360 10.3390/polym17233095 258604547 RAZ_Oseli_Alen_2025.pdf RAZ_Oseli_Alen_2025.pdf 1 B5D851E04C8C58B079371B7D8A5CB6C4 c6724c8ebcef680f3df3c6157327d296041a20ed0b46d38f56154a1668b21f04 e2c60e74-c9f0-11f0-9328-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=222474 https://www.mdpi.com/2073-4360/17/23/3095 1 85d749f7-c9f0-11f0-9328-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=222473 Fakulteta za strojništvo 0 0 0