The single carcass offshore rubber hose is mainly composed of layers of steel wire, cords, and rubber materials, and it is used worldwide for oil and gas transport systems. A nonlinear finite element offshore rubber hose model is created to calculate the collapse response of the hose by the bending moment using Abaqus™ software. The results demonstrate, the range of diameter and the variation of the pitch of the helix wire have a great influence on the collapse resistance of the hose. The stress distribution trend of the cord is different on compressed and stretched zone. The finite element model can predict the collapse characteristics of the offshore rubber hose and provide guidance for the structure design of the hose.
The single carcass offshore rubber hose is bonded rubber hose with fiber cords and helix wire steel, which is widely used in offshore oil transport systems (Amaechi et al., 2021). The characteristics of the single carcass offshore rubber hose are larger bore, high pressure, high strength combined with flexibility, and excellent fatigue resistance. The single carcass hose group is consisted by the end reinforced hose, mainline hose, taper hose, tail hose, and barbell rail hose, and it is used in single point mooring in 1970s (Katona et al., 2009; Ziccardi, 1970) showed in Fig. 1. A typical single carcass offshore rubber hose is depicted in Fig. 2. In the illustration, the steel end fitting includes the flange, the nipple, and the annular ribs, which are welded together. The nipple, the inner rubber layers, the reinforcement layers, and the helix wire are vulcanized to each other.
The main standard for the single carcass offshore rubber hose is API 17K ( 2018), API 17B (2014), and the OCIMF (2009), which give the rules about manufacturing and purchasing. But there are no specific instructions for the design and evaluate the safety of the hose. The single carcass rubber hose is affected by the operation and various environments, and the load on the hose is consisted of the axial load, torsion load and bending load and so on. One of the main loads on the hose connected to the FPSO or CALM is the bending load in the floating hose system (Paruolo et al., 2020; Tonatto et al., 2018), and the hose is likely to excessive bending during installation (G P Drumond et al., 2018), which is shown in Fig. 1. Excessive bending load is easy to cause local crushing and buckling of the hose structure, which showed in Fig. 2.
