The Kelvin-Voigt Model's Suitability to Explain the Viscoelastic Properties of Anticorrosion Bitumen at Large Shear Strain in Subsea Cables and Umbilicals

Abstract

Bitumen is used as anticorrosion to protect steel armor wires in subsea cables and umbilicals. Bitumen’s viscoelastic behavior influences the mechanical properties of the cables, in particular the bending stiffness. UFLEX2D is a software tool for mechanical analyses of cables and similar structures, which can include the viscoelastic effect of bitumen using a Kelvin-Voigt model. This paper evaluates how well the Kelvin-Voigt model is able to resemble bitumen’s viscoelastic properties. It is concluded that the Kelvin-Voigt model’s lack of temperature dependence can be managed, while the model’s handling of strain amplitude is too simple to fully explain bitumen’s behavior. It is also concluded that the Kelvin-Voigt model has limited abilities to resemble the frequency response of bitumen.