20.500.12556/RUL-181942 A novel numerical model for fire analysis of post-tensioned concrete beams with curved unbonded tendons This paper presents a novel numerical framework for the fire analysis of post-tensioned concrete beams with curved unbonded tendons. The framework consists of three sequential steps: (i) fire development in the structural surroundings, (ii) hygro-thermal analysis of the cross-section, and (iii) mechanical analysis, where the reinforced concrete beam and prestressing tendons are represented as separate interacting components. The core contribution lies in step (iii), where a new beam-type finite element formulation is proposed. Unlike conventional shell or solid models, the approach substantially reduces the number of degrees of freedom and thereby the computational cost. Additional efficiency is achieved by interpolating strains instead of displacements, which eliminates numerical locking often present in alternative formulations. The model further accounts for material nonlinearity (allowing implicit or explicit consideration of transient and creep strains) while the kinematics are linearized, enhancing robustness. These features collectively enable efficient analysis of large structural systems rather than isolated members. Validation against experimental data confirms accuracy and numerical stability, while the modest computational demand supports routine application on standard personal computers. Finally, the model is applied in a parametric study investigating whether the EN 1992-1-2 stress–strain model for concrete implicitly accounts for creep effects in fire-exposed prestressed beams. prestressed concrete unbonded curved tendon post-tensioning fire analysis hygro-thermal analysis implicit creep Eurocode 2 nevezana ukrivljena tetiva naknadno napenjanje požarna analiza higrotermična analiza implicitno lezenje Evrokod 2 true false true Angleški jezik Slovenski jezik Članek v reviji 2026-04-20 13:14:06 2026-04-20 13:14:16 2026-04-21 04:42:30 0000-00-00 00:00:00 2026 0 0 16 str. Vol. 163, art. 104807 Sep. 2026 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 69 1873-7226 10.1016/j.firesaf.2026.104807 275229443 https://www.sciencedirect.com/science/article/pii/S037971122600175X 1 d6031ec8-3ca9-11f1-b0ab-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=232753 Kocman,_Bratina,_Kolsek-A_novel_numerical_model_for_fire_analysis_of_post-tensioned_concrete_beams_with_curved_unbonded_tendons.pdf Kocman,_Bratina,_Kolsek-A_novel_numerical_model_for_fire_analysis_of_post-tensioned_concrete_beams_with_curved_unbonded_tendons.pdf 1 E0C787DFA85765A70E487BF0B6E5F34B 08f2f6c227c60892d208720d053349e3ad4186bc479984520086a559ec8dd74c 1ead3e26-3caa-11f1-b0ab-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=232754 Fakulteta za gradbeništvo in geodezijo 0 0 0