Predictive/fitting capabilities of differential constitutive models for polymer melts - reduction of non-linear parameters in the eXtended Pom-Pom model

0428884 - ÚH 2015 RIV DE eng J - Journal Article
Pivokonský, Radek - Filip, Petr
Predictive/fitting capabilities of differential constitutive models for polymer melts - reduction of non-linear parameters in the eXtended Pom-Pom model.
Colloid and Polymer Science. Roč. 292, č. 11 (2014), s. 2753-2763. ISSN 0303-402X. E-ISSN 1435-1536
R&D Projects: GA ČR GA103/09/2066
Institutional support: RVO:67985874
Keywords : constitutive mode * XPP model * LDPE materials * strain hardening * elongational flow * shear flow
OECD category: Fluids and plasma physics (including surface physics)
Impact factor: 1.865, year: 2014
http://link.springer.com/article/10.1007%2Fs00396-014-3308-7

A phenomenological modification of the eXtended Pom-Pom (XPP) model is proposed with the aim to reduce the number of free nonlinear parameters. The modified XPP model includes three parameters per mode in total (two linear viscoelastic parameters—linear relaxation time λ and shear modulus G, and one nonlinear parameter). The original XPP model contains five parameters (two linear viscoelastic parameters and three nonlinear ones, one nonlinear parameter participates in the second normal stress difference prediction). The predictive/fitting capabilities of the modified model are compared with the Giesekus, eXtended Pom-Pom, and modified Leonov models using various low-density PE materials in steady and transient shear and uniaxial elongational flows. It has been found that the modified model is capable of predicting/fitting the rheological properties, with the exception of the second normal stress difference, for studied LDPE materials with sufficient accuracy, including strain hardening in uniaxial elongational flow.
Permanent Link: http://hdl.handle.net/11104/0235691