Utilizing deployable morphing structures in ocean engineering applications is a practice in its infancy. We propose an inflatable tubular beam using a hydrogel bead's ability to absorb water to achieve the desired structural shape and strength. It is therefore essential to know the strength of the morphed structure. The first step is to study the strength of the simple structural element. This paper focuses on the numerical modelling of bending tests on inflatable tubular structures filled with hydrogel beads to elucidate the various deformations of multiple compositions of bead/tube structures using the discrete element method. The properties of the tubes and beads were obtained, then calibrations of the micro numerical parameters were conducted. Twenty-four cases of bending tests were simulated. The results show that the degree to which the beads are filled, along with the bead's radius, have a direct effect on the composite structure's strength against deformation. (C) 2019 Elsevier B.V. All rights reserved.