Torsion dissipated energy of hard rubbers as function of hyperelastic deformation energy of the Yeoh

0497769 - ÚT 2019 RIV CZ eng J - Journal Article
Šulc, Petr - Pešek, Luděk - Bula, Vítězslav - Košina, Jan - Cibulka, Jan
Torsion dissipated energy of hard rubbers as function of hyperelastic deformation energy of the Yeoh.
Applied and Computational Mechanics. Roč. 12, č. 1 (2018), s. 111-118. ISSN 1802-680X
R&D Projects: GA ČR GA16-04546S
Institutional support: RVO:61388998
Keywords : first invariant deformation * simple shear * deformation energy
OECD category: Applied mechanics

In this paper, we are proposing a new formulation of dissipated energy of hard rubbers as a function of the deformation energy expressed by the Yeoh hyperelastic model. Torsion deformation is considered as a planar deformation of a simple shear on the surface of a cylinder. Thus the deformation energy is dependent only on the first invariant of strain. Based on the experiment, a “hyperelastic proportional damping” (HPD) is proposed for hard rubbers under finite strains. Such damping is analogical to the model of proportional damping in the linear theory of viscoelasticity, i.e. the dissipated energy is proportional to the deformation energy multiplied by the frequency of dynamic harmonic loading. To obtain the experimental data, samples of hard EPDM rubbers of different harnesses were dynamically tested on a torsional test rig for different frequencies and amplitudes. The Yeoh model is chosen since the deformation function is dependent only on the first strain invariant for the description of the simple shear of a surface cylinder. The Yeoh constants are evaluated by curve fitting of the analytical stress function to the experimental torsion stress-deformation curve. The constants are used to express the deformation energy of the Yeoh model for specific cases of tested rubbers. The coefficients of hyperelastic proportional damping are evaluated on the basis of experimental results.
Permanent Link: http://hdl.handle.net/11104/0293936