Internal stress model for pre-primary stage of low-stress creep

0346624 - ÚFM 2011 RIV GB eng J - Článek v odborném periodiku
Kloc, Luboš
Internal stress model for pre-primary stage of low-stress creep.
Journal of Physics: Conference Series. Roč. 240, - (2010), 012086. ISSN 1742-6588. E-ISSN 1742-6596.
[ICSMA-15 (15th International Conference on the Strength of Materials). Dresden, 16.08.2009-21.08.2009]
Grant CEP: GA AV ČR IAA200410701
Výzkumný záměr: CEZ:AV0Z20410507
Klíčová slova: low-stress creep * transient stage * elastoplastic model
Kód oboru RIV: BM - Fyzika pevných látek a magnetismus

Initial transient stage in low-stress creep experiments was observed in all such experiments. Recently, evidences were presented that this stage cannot be considered as a normal creep primary stage, though the shape of the creep curve is similar. The strain reached during this so called pre-primary stage is fully recoverable upon unloading; the internal stresses must play important role in the effect. Model of standard linear anelastic solid was modified by introduction of creeping body instead of viscous dashpot. Both power law and hyperbolic sine creep law were used to fit observed creep curves of model and structural materials. Mainly the model using hyeprbolic sine creep law provides good fit to individual creep curves and sets of creep curves at different stresses.
Trvalý link: http://hdl.handle.net/11104/0187602