MICRO/MACROMECHANICAL ANALYSIS AND OPTIMIZATION OF THE FLEXURAL STRENGTH OF LaRC-SI/PmPV/CNT NANOCOMPOSITE SQUARE PLATE USING GENETIC ALGORITHM

摘要

The nanoscale properties of the reinforcement-interphase and the macroscale behavior of nanocomposite should be considered altogether in order to exploit the maximum potential of nanostructured materials. For instance, aside from the high cost of carbon nanotube (CNT) manufacturing, adding a large amount of CNT to the polymeric matrix can result in enhancement of the probability of stress singularities and stress concentrations at the interphase, which may consequently decrease the failure strength of the nanocomposite. In this study, single-wall carbon nanotube (SWCNT) is the reinforcement sheathed by a soluble polymer poly(m-phenylene vinylene-co-2,5-dioctoxyp-phenylene) (PmPV) as the interphase was embedded in a Langley Research Center-Soluble polyImide (LaRC-SI) polymeric matrix. We employed an elitist multiobjective genetic algorithm coupled with macromechanical failure criteria to optimize the volume fraction of CNTs in a mechanically loaded laminate as well as the weight of the structure without loss of strength. The approach of minimizing the percentage of additive without compromising the desired properties of the final product has several applications in material design and biomechanics, especially in those applications where the use of a minimal amount of additive is desirable.