Parametric analysis of an offloading hose under internal pressure via computational modeling Maikson L.P. Tonatto a, * , Volnei Tita b , Ricardo T. Araujo c , Maria M.C. Forte a , Sandro C. Amico a a Post-Graduation Program in Mining, Metallurgical and Materials Engineering, Federal University of Rio Grande do Sul, LAPOL, Av. Bento Gonçalves, 9500, 91509-900, Porto Alegre/RS, Brazil b Department of Aeronautical Engineering, S~ ao Carlos School of Engineering, University of S~ ao Paulo, Av. Jo~ ao Dagnone, 1100, 13563-120, S~ ao Carlos/SP, Brazil c E&P, Petrobras, Av. Chile, 330, CEP 20031-170, Rio de Janeiro/RJ, Brazil article info Article history: Received 25 April 2016 Received in revised form 6 September 2016 Accepted 24 October 2016 Keywords: Floating hose design Finite element modeling Parametric analysis Composite structure Burst pressure calculations abstract An offloading hose is a complex structure, mainly composed of rubber, cords and steel coil, which is used worldwide for oil production and transport systems such as offloading operations in Catenary Anchor Leg Mooring (CALM) buoy. The cords play a vital role on the hose, being responsible for resisting to the applied internal pressure. In this work, finite element models with axisymmetric and 3D elements have been developed to estimate burst pressure of a double carcass floating hose with nominal diameter 20 00 and design pressure of 21 bar. Finite element models have been developed in commercial software using reinforcement bars (rebars) to represent cords behavior. A parametric analysis has been performed, and mesh convergence was also evaluated to predict stress concentration in the failure regions. In addition, complex non-linear calculations for the contact between the hyperelastic rubber, which was modelled with Arruda-Boyce's, and the polyester, polyamide and hybrid reinforcement cords, modelled with Marlow's theory, were considered in the FEM. Maximum load in the REBAR layers was used to predict failure in the cords. Actual full-scale experiments were carried out for comparisons, prototypes with different number of layers and cord material have been manufactured. Burst pressure tests of the carcasses was the criterion used to evaluate the minimum requirements of the Oil Companies International Marine Forum (OCIMF). A maximum deviation of 7.5% was found between computational predictions and experimental results. Therefore, the proposed computational model was considered suitable to be used in the design of these hoses, especially for parametric analysis. © 2016 Elsevier Ltd. All rights reserved. 1. Introduction Flexible pipes are used in a variety of applications and may be classified into unbonded and bonded flexible pipes, being both comprised of reinforcements embedded into a flexible polymeric matrix, which is usually an elastomer [1,2]. There are * Corresponding author. E-mail addresses: maikson.tonatto@ufrgs.br (M.L.P. Tonatto), voltita@sc.usp.br (V. Tita), ricardoteles@petrobras.com.br (R.T. Araujo), mmcforte@ufrgs.br (M.M.C. Forte), amico@ufrgs.br (S.C. Amico). Contents lists available at ScienceDirect Marine Structures journal homepage: www.elsevier.com/locate/marstruc http://dx.doi.org/10.1016/j.marstruc.2016.10.008 0951-8339/© 2016 Elsevier Ltd. All rights reserved. Marine Structures 51 (2017) 174e187