PREDICTION OF THE MECHANICAL BEHAVIOR OF A SANDWICH TUBULAR STRUCTURE BASED ON NATURAL FIBERS UNDER QUASI-STATIC AND FATIGUE LOADING

Abstract

To provide a new solution for hydrogen transportation that is lightweight and less expensive, the current contribution concentrates on the mechanical behavior of eco-sandwich pipes constructed of biocomposite materials under static and cyclic loads, using three-dimensional elasticity theory. To achieve the sizing of the tubular eco-sandwich pipelines, a multiscale characterization is performed, beginning with the micro- and macro-mechanical scales. The micromechanical approach is used to predict the mechanical properties of bio skins before analyzing the whole cylinder sandwich structure under different loadings. The second step focuses on understanding the behavior of a sandwich element in the tubular structure through a macro-mechanical model. The analytical and 3D numerical models are developed through this contribution to investigate the mechanical behavior of sandwich pipe under static and cyclic internal pressure loading. The suggested models provide an exact solution for stresses, strains, and displacement of sandwich pipe, which is made of epoxy material for the core layer and reinforced materials with an alternate layer for the skin layers. The main aim of this work is to evaluate the potential applications of bio-fibers in order to replace glass synthetic fibers generally employed in sandwich pipes. In this subject, a failure analytical analysis was developed using the Tsai-Wu criterion for skins and Von-Mises for the core. In order to increase the rigidity of a biocomposite sandwich and reduce the gap compared with a synthetic sandwich, the main results show that a gradual reinforcing of layer numbers was chosen, which permitted the best behavior. On the other hand, the ultimate pressure and safety factors obtained by increasing biocomposite layers are significant for composite transportation pressure pipelines and can play the same role at this stage of analysis.