Design And Manufacturing On Grid Composite Cylinder Structures

Grid structural composite material is the most efficient load bearing structures with many advantages such as ultra-light weight and high load bearing capacity. Therefore, it has potential applications in aeronautical and space engineering. Design, manufacturing process and loading capacities of carbon fiber reinforced epoxy composite cylinder with grid structure was studied in this paper. Cell style and structural parameters of the grid structure cylinder were studied with the finite element method, and the optimal style and structural parameters were obtained. Manufacturing of the grid composite cylinder structures (GCCS) by silicon rubber mould assistant filament winding process was investigated and loading capacities of GCCS under axial compression loading was evaluated.The finite element model (FEM) of the GCCS with diamond cell, triangle cell, hexagon cell, square cell and triangle-hexagon-mixed cell were built respectively. The analyzed results show that the triangle-hexagon-mixed style is the optimal style all in stiffness, load-to-weight ratio and stability.Effects of structural parameters on internal stiffness and load-to-weight ratio of the GCCS were studied and the optimal structural parameters were obtained. The optimal configuration parameters of the composite grid load-carrying cylinder structures with outer diameter of 500mm and height of 698mm were: helical angleφ=30°, ratio of width b and the height h of ribs h:b=2:1 and h=10mm, b=5mm, the GCCS bottom perimeter should be divided into 20 equivalent parts by the ribs and the amount of circumferential ribs should be 10. Results show that stiffness, maximal compression loading and critical buckling loading of a structure with a hatch decreased by 23.6%, 85% and 26.6% respectively.The GCCS samples were fabricated successfully by silicon rubber mould assistant filament winding process and vacuum-bagging. Effects of manufacturing parameters such as resin system and curing processes on quality of GCCS were studied, and optimal process parameters were obtained.Axial compressive property of GCCS samples was tested. The maximum compressive load, load-to-weight ratio and stiffness of the GCCS are 192.15kN, 68.14kN/kg and 91.51kN/mm, respectively. The dominated failure modes for the 2D-GCCS cylinders were delamination and fracture of the intersection of two helical ribs.