FIGURE 3.12 Polishing of the specimen embedded in mounting material. FIGURE 3.13 Photomicrograph of a polished cross section.(Courtesy ofS.Nilsson,FOI,Stockholm,Sweden.) 4.When the specimen is polished,it is ready to be examined in the optical microscope.Take a photograph of a polished cross section like the one shown in Figure 3.13. 3.3.2.2 Determination of Fiber Volume Fraction The fiber volume fraction can be determined from the photomicrograph in two ways,as illustrated in Figure 3.14.One way is to determine the total area of the fibers in a given area of the micrograph.This can be done directly with a quantitative image analyzer or by counting the number of fibers in the area and calculating the total fiber area from their average diameter.The fiber volume fraction is determined as Vi=A/A (3.5) ©2003 by CRC Press LLC4. When the specimen is polished, it is ready to be examined in the optical microscope. Take a photograph of a polished cross section like the one shown in Figure 3.13. 3.3.2.2 Determination of Fiber Volume Fraction The fiber volume fraction can be determined from the photomicrograph in two ways, as illustrated in Figure 3.14. One way is to determine the total area of the fibers in a given area of the micrograph. This can be done directly with a quantitative image analyzer or by counting the number of fibers in the area and calculating the total fiber area from their average diameter. The fiber volume fraction is determined as Vf = Af /A (3.5) FIGURE 3.12 Polishing of the specimen embedded in mounting material. FIGURE 3.13 Photomicrograph of a polished cross section. (Courtesy of S. Nilsson, FOI, Stockholm, Sweden.) TX001_ch03_Frame Page 53 Saturday, September 21, 2002 4:51 AM © 2003 by CRC Press LLC