ANALYZING INTERLAMINAR SHEAR STRENGTH OF MULTI-SCALE COMPOSITES VIA COMBINED FINITE ELEMENT AND PROGRESSIVE FAILURE ANALYSIS APPROACH

摘要

Newly developed multi-scale composites use nano-particles in fiber reinforced composites to dramatically increase strength and stiffness in the out-of-plane direction. Small weight percent of nano-particles significantly improves the delamination resistance. Analyzing multi-scale composites is a challenging issue, requiring analysts to consider the mechanics from nano-scale to macro-scale. The approach developed in this paper demonstrates a powerful, easy and time efficient methodology that combines analytical and numerical analyses with progressive failure analysis. First, calculates the effective anisotropic properties for enhanced matrix that contains aligned nano-particles of known aspect ratio, strength and stiffness. Second, calculates the isotropic enhanced matrix properties using micro-mechanics. The enhanced matrix is assumed to be same as interphase around the conventional fibers in the neat matrix. Then, progressive failure analysis is performed to characterize/simulate the multi-scale composites and structural components. Simulation results indicate 21.5 percent increase in interlaminar shear strength for 1 weight percent multi-walled carbon nanotubes in the advanced material. The results obtained compare reasonably well with similar test data (18.2 percent increase in interlaminar shear strength for 1 weight percent multi-walled carbon nanotubes).