| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1719855 | Applied Ocean Research | 2016 | 9 Pages |
•An innovative model to investigate linear viscoelastic behavior of flexible pipes under axisymmetric loads in time domain is established.•The model is derived from an equivalent linear elastic axisymmetric model by invoking the elastic-viscoelastic correspondence principle.•Formulations describing the behavior of the helical layers are based on a combination of differential geometry concepts and Clebsch–Kirchhoff equilibrium equations.•Approximate analytical solutions for some important parameters responding the mechanical behavior of flexible pipe are observed taking time-dependent characteristics of polymeric layers into consideration.•It is clear that the relationship between axial force and elongation is non-linear and a hysteretic response appears.
The challenges for determining the mechanical behavior of flexible pipes mainly arise from highly non-linear geometrical and material properties and complex contact interaction conditions between and within layers components. This paper develops an innovative model to investigate the linear viscoelastic behavior of flexible pipes under axisymmetric loads in time domain. The model is derived from an equivalent linear elastic axisymmetric model by invoking the elastic-viscoelastic correspondence principle. Analytical formulations that describe the behavior of the metallic helical layers based on a combination of differential geometry concepts and Clebsch–Kirchhoff equilibrium equations for initially curved slender elastic rods are presented. The elastic response of the homogenous polymeric cylindrical layers is also presented. The assemblage of both types of governing algebraic equations that approximate analytical solutions for force and moment distributions, deformations in each layer, as well as contact pressure between near layers, taking time-dependent characteristics of polymeric layers into account are provided and it is clear that the relationship between axial force and elongation is non-linear and encompasses a hysteretic response. Besides, the creep behavior in axial direction can also be found. Some insights into the differences in the behavior for several loading conditions are discussed by considering variable frequencies.
