Analysis of intermetallic swelling on the behavior of a hybrid solution for compressed hydrogen storage – Part I: Analytical modeling Abdelkader Hocine a,b, * , David Chapelle b , Lamine M. Boubakar b , Ali Benamar c , Abderrezak Bezazi d a University Hassiba Benbouali, BP. 151, Chlef 02000, Algeria b Institute FEMTO-ST, Dept. LMARC, 24, Epitaphe street, 25000 Besançon, France c ENSET, Department of Mechanical Engineering, BP. 1523, Oran 31000, Algeria d University 08 Mai 1945, BP. 401, Guelma 24000, Algeria article info Article history: Received 25 September 2009 Accepted 23 November 2009 Available online 27 November 2009 Keywords: Laminates Intermetallics Failure analysis abstract This study focuses on the mechanical response of a hybrid solution dedicated to gaseous hydrogen stor- age. This solution is made of a carbon/epoxy composite overwrapped on a metal liner first coated with intermetallic material. The composite helps to reinforce the structure, while the liner prevents it from any leakage. In case of deficiency, the intermetallic material behaves as a sponge and interrupts the leak- age by absorption and micro-cracks reduction. This hybrid solution or this specific use of intermetallic material has never been presented before. The laminate composite is anisotropic, whereas the liner is an elastic–plastic material. The intermetallic is purely thermo elastic and its study is limited to its mechanical contribution. Using these hypotheses, the suggested analytical model provides an exact solu- tion for stresses and strains on the cylindrical section of the hybrid solution submitted to thermomechan- ical static loading and hydrogen leakage. The swelling effect of the intermetallic on the behavior of the structure is then investigated. Crown Copyright Ó 2009 Published by Elsevier Ltd. All rights reserved. 1. Introduction Hydrogen is considered as one of the more promising energy vectors of the future. It can be used as a fuel in many applications. However, this requires several technological hurdles to be cleared, especially the one concerning its storage. Storage must offer a high degree of safety as well as allowing ease of use in terms of energy density and dynamics of fuel storage and controlled release. The use of composite materials is an extremely interesting alternative to metallic materials in the construction of tanks. In- deed, these materials are characterized by their lightness, rigidity, good fatigue strength, and corrosion resistance when their compo- nents are not metallic [1]. Thin or thick walled tanks are widely used in several branches of engineering, such as the storage of compressed hydrogen, liquefied and compressed natural gas [2,3]. The choice of material for the liner is crucial whenever the ves- sel is designed to contain gas under high pressure, to prevent for instance the diffusion through the wall, or when it is designed to contain liquid under severe temperature conditions. The over- wrapped composite aims to ensure the mechanical strength. This storage can provide several advantages: it ensures a perfect partic- ipation between the liner and the composite hull, it uses the over- all resistance of the fiber in tension and it allows reaching weight saving up to 50% in comparison with all metal vessels [4,5]. In many metals, the hydrogen embrittlement decreases drasti- cally the failure strength. Experimental observations [6,7] and the- oretical calculations [8–10] have demonstrated that dissolution of hydrogen atoms increases the dislocation mobility and promote highly localized plastic processes, which eventually lead to ductile rupture. In the case of hydrogen storage, the embrittlement phe- nomenon can be responsible of the formation of cracks in the alu- minum liner and can lead to micro-leaks. Based on previous works, Chapelle and Perreux [11] developed an analytical procedure to predict the behavior of the cylindrical section of a type 3 vessel for hydrogen storage applications. The anisotropic plastic flow of the liner and the damage for the com- posite were taken into account. Hocine et al. [12] present an exper- imental, analytical and FEM simulation investigation of a hydrogen storage vessel of type 3. The suggested analytical model provides an exact solution for stresses and strains on the cylindrical section of the vessel solution submitted to mechanical static loading. Some analytical results are compared with experimental and the finite element solutions, a good correlation is observed. The present study concerns the development of an improved high pressure hydrogen storage vessel (Fig. 1). In this solution, a hydrogen absorbing intermetallic between the aluminum liner 0261-3069/$ - see front matter Crown Copyright Ó 2009 Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.matdes.2009.11.048 * Corresponding author. Address: University Hassiba Benbouali, BP. 151, Chlef 02000, Algeria. Tel./fax: +213 27 72 28 77. E-mail addresses: hocinea_dz@yahoo.fr (A. Hocine), david.chapelle@univ-fcom- te.fr (D. Chapelle), lamine.boubakar@univ-fcomte.fr (L.M. Boubakar), benamar_d- z@yahoo.fr (A. Benamar), ar_bezazi@yahoo.com (A. Bezazi). Materials and Design 31 (2010) 2435–2443 Contents lists available at ScienceDirect Materials and Design journal homepage: www.elsevier.com/locate/matdes