Issue 37

M. S. Raviraj et alii, Frattura ed Integrità Strutturale, 37 (2016) 360-368; DOI: 10.3221/IGF-ESIS.37.47 365 2 3 4 a 2 a a a a a W 0.886 4.64 13.32 14.72 5.60 a W W W W 1- W 3/ 2 f W                                                                   (2) -1 0 1 2 3 4 5 6 7 8 9 10 11 0 2 4 6 8 10 12 AL+3wt%TiC a/W=0.5 Load,kN CMOD,mm B/W=0.2 B/W=0.3 B/W=0.4 B/W=0.5 B/W=0.6 B/W=0.7 Figure 7 : Load vs. crack mouth opening displacement curves for Al6061+wt3% TiC composite of various B/W ratios. 0 2 4 6 8 10 0 1 2 3 4 5 6 Al+5%TiC a/W=0.5 Load,kN CMOD,mm B/W 0.2 B/W 0.3 B/W 0.4 B/W 0.5 B/W 0.6 B/W 0.7 Figure 8 : Load vs. crack mouth opening displacement curves for Al6061+wt5% TiC composite of various B/W ratios. The calculated K Q is plotted against various B / W ratios for various Al6061-TiC composites. Fig. 10 shows the variation of K Q vs. B / W ratios for various Al6061-TiC composites. It is observed from Fig.10 that the K Q decreases with increase in B / W ratios and found to remain constant for B / W ≥0.5. This constant value of K Q for B / W ≥0.5 prevail the plane strain fracture toughness (K IC ) of the composite. For B / W ≤0.4, the value of K 1C can be considered the real plane stress fracture toughness. It is analyzed from Fig. 10 that the increase of TiC from 3wt% to 5wt% in Al6061 matrix composites, there will be a decrease in fracture toughness from 19.2 MPa√m to 16.4 MPa√m and further increase of TiC to 7wt% the