FLEXURAL RESPONSE OF REAL WOVEN COMPOSITE ENABLED VIA XCT-DRIVEN FINITE ELEMENT MODELING
Topic(s) : Material and Structural Behavior - Simulation & Testing
Co-authors :
Kamran A. KHAN (UNITED ARAB EMIRATES), Israr UD DIN (UNITED ARAB EMIRATES), Adnan AHMED (UNITED ARAB EMIRATES)Abstract :
Conventionally, deployable folding structures were being developed using metallic structures. Nowadays, light-weight deployable folding structures with less number of parts are manufactured using fiber reinforced polymer composites (FRPCs) with dual-matrix systems. The conventional epoxy with fiber reinforcement is used in the stiff region, whereas a high stretching capability matrix such as elastomers are used in the flexible region. The stiff region is responsible for maintaining the deployed shape and provides strength to the folding structures. On the other hand, the flexible regions act as elastic hinges and fold/unfold upon deployment, hence are subjected to flexure loading defining the moment-curvature behavior of the overall folding structure. The determination of the moment-curvature of the folding structures are of utmost importance for which either reliable customized experimental set-up is required or sophisticated modeling techniques driven by accurate modeling description of the fold region is needed. The approach based on the real 3D voxel based description of the FRPCs laminates can enable us to provide an accurate 3D model to be used in the finite element (FE) modeling.
In this work, X-ray micro computed tomography (XCT) based 3D model of the flexible region is developed which is composed of a single-layer plain-weave glass fiber reinforced elastomer. A representative unit cell called as representative volume element (RVE) of the flexible region was modelled by supervised segmentation of the XCT image stacks into 3D voxels associated to fibers having anisotropy and local orientation and isotropic matrix i.e. elastomer. Owing to the fact that there exist fibers' undulating patterns and also the material properties of both the fibers and the matrix are substantially different, therefore, it is expected that the bending response utilizing the real RVE will provide a more reliable bending-curvature response. The bending stiffness of the real RVE was determined by applying a moment on one side whereas periodic boundary conditions (PBCs) and symmetry BCs were applied to the remaining three sides of the 3D RVE model in FE commercial software ABAQUS®. To compare bending stiffness, RVE models of homogenized elastomer laminate meshed with 3D solid FE element C3D8R available in ABAQUS® were also subjected to bending maintaining the same values of curvature. Quasi-static bending analysis for small strains was conducted in ABAQUS®, utilizing the linear elastic properties of constituent materials. It is concluded that a significant contrast was found in the bending stiffness obtained with the two approaches using real RVE and homogenized RVE during bending of the flexible region in the deployable folding structure.
In this work, X-ray micro computed tomography (XCT) based 3D model of the flexible region is developed which is composed of a single-layer plain-weave glass fiber reinforced elastomer. A representative unit cell called as representative volume element (RVE) of the flexible region was modelled by supervised segmentation of the XCT image stacks into 3D voxels associated to fibers having anisotropy and local orientation and isotropic matrix i.e. elastomer. Owing to the fact that there exist fibers' undulating patterns and also the material properties of both the fibers and the matrix are substantially different, therefore, it is expected that the bending response utilizing the real RVE will provide a more reliable bending-curvature response. The bending stiffness of the real RVE was determined by applying a moment on one side whereas periodic boundary conditions (PBCs) and symmetry BCs were applied to the remaining three sides of the 3D RVE model in FE commercial software ABAQUS®. To compare bending stiffness, RVE models of homogenized elastomer laminate meshed with 3D solid FE element C3D8R available in ABAQUS® were also subjected to bending maintaining the same values of curvature. Quasi-static bending analysis for small strains was conducted in ABAQUS®, utilizing the linear elastic properties of constituent materials. It is concluded that a significant contrast was found in the bending stiffness obtained with the two approaches using real RVE and homogenized RVE during bending of the flexible region in the deployable folding structure.