Bitumen is commonly used as anticorrosion protection for armor wires in subsea power cables, umbilicals, and power umbilicals. Bitumen's viscoelastic behavior influences the cable's mechanical properties. The present paper derives a simple, analytical model of bitumen-coated armor wires. The model calculates the axial stresses of the armor wires and the armor wires' contribution to the cable's bending stiffness. The model shows that there is a phase shift between the sinusoidal curvature oscillations and the corresponding armor wire stresses and cable bending moment. Two examples show that the armor wire stresses and the cable's bending stiffness are strongly temperature-dependent. The purpose of the novel model is to calculate bending stiffness, fatigue stresses, and capacity (allowed combinations of axial cable tension and cable bending curvature) more accurately and to study these variables' sensitivity to temperature and frequency. The model may also be included in calculations of bitumen's influence on VTV damping.
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