Papers by Keyword: Advanced Composites

Abstract: This paper presents a new concept of forming 3D hierarchical carbon nanotube (CNT) and carbon fiber (CF) reinforced composites by using a low temperature grafting method that connects CNTs to CF surface by covalent bonding. By using amorphous carbon to join the free ends of two cantilever CNTs, it is shown via in situ scanning electron microscope (SEM) pulling out experiments that the strengths at the joint between CF-CNT and CNT-CNT junction are high and breakage occurs in CNT itself. This offers evidence that the maximum load in a typical bridging load-displacement curve could be increased, which in turn can potentially increase intralaminar and interlaminar fracture toughness of 3D multiscale CNT-CF reinforced composites.

Abstract: In the present study, both critical buckling load maximization and face-sheet laminate thickness minimization problems for the composite sandwich panel, subjected to bi-axial compressive loading under various imposed constraints have been investigated using genetic algorithms. In the previously published work, the optimization of simple composite laminate panels with only even number of laminae has been considered [1, 3]. The present work allows the optimization of a composite sandwich panel with both even and odd number of laminae in the face-sheet laminates. Also, the effects of the bending-twisting coupling terms (D₁₆ and D₂₆) in bending stiffness matrix which were neglected in the previous studies [1, 2, 3], are considered in the present work for exact solutions. In addition effect of both balanced and unbalanced face-sheet laminates on the optimum solutions have also been investigated, whereas only balanced laminates were considered in the previous studies [1, 2, 3].