STRUCTURAL CONCEPT DESIGN OF FUNCTIONALLY GRADED COMPOSITE MATERIALS (FGCM) FOR SPACE EXPLORATION

摘要

A promising new alternative material for composite sandwich is emerging. In this new functionally graded composite material (FGCM), a monolithic solid of the designed properties replaces the two facesheets and the core that is common in a typical sandwich structures. In this seamless composite beam the variation of the through-thickness properties (strength, stiffness and densities) mimics the conventional sandwich structure, while the interfaces are removed. This innovative composite beams design is fabricated using the mixtures of fibers and resins of different grades and foaming agents in special molds with controlled curing technique. The properties are tailored by modulating the fiber volume fraction and the matrix through-the-thickness of the structure. The obvious advantage of such a seamless laminate is the mitigation of the most common failure mechanism of the conventional sandwich, namely, is the interface failure by delamination or shear. The characterization, analysis, and prediction of failures in these innovative panels, which are subjected to a variety of loading scenarios is discussed.