Interlocked composite grids design and manufacturing

Composite grid structures made from pultruded unidirectional glass or carbon ribs promise to provide unmatched performance/cost combination of any composite panels. A new manufacturing method for a square grid using slotted joint and adhesive bonding (Interlocked Composite Grid or ICG) with pultruded ribs has been developed. Compared to previously proposed grids, it is mass producible at low cost. It has large potential for many applications, particularly for large civil structures. Equivalent stiffness models for the proposed ICG, in equivalent plate stiffness matrix form and equivalent engineering constant form, have been formulated and verified for the flexural behavior of ICGs. The effects of the slots have been considered and integrated in the model. Design guidelines with equivalent engineering constants, and approximate cost estimation rules have been established. An example problem has been solved to demonstrate the simplicity of the design rules. ICG beams and panels have been built and tested under static and dynamic flexural loading. Valuable test data are provided and superior mechanical properties, such as high damage tolerance, resilience, and durability have been demonstrated.