Figure 2-24. Use of 3D weaving to create a branched structure . . . . . . . . . . . . 2-32
Figure 2-25. An integrally woven skin/stiffener preform . . . . . . . . . . . . . . . . . . . 2-32
Figure 2-26. A stitched skin/stiffener assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-33
Figure 3-1. The Moduli of 2D Braids and Equivalent Tape Laminates . . . . . . . . 3-5
Figure 3-2. Comparison of (a) unnotched and (b) notched strengths
of 5-harness satin weave laminate and equivalent tape
laminate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
Figure 3-3. Comparison of shear strengths of various T300/934 weaves,
showing effect of crimp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8
Figure 3-4. Comparison of unnotched and open hole tensile strengths
for two triaxial braids and equivalent tape laminates. . . . . . . . . . . . . 3-9
Figure 3-5. Tensile strengths of stitched and unstitched IM7/3501-6
laminates. Stitching with 0.125 in. (3.1 mm) pitch
(between penetrations within a row) and 0.20 in. (5.0 mm)
spacing between the stitching rows . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11
Figure 3-6. Compression strengths and CAI data for stitched and
unstitched laminates. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11
Figure 4-1. Arrays of ogive microcracks in (a) an AS4/1895 tape
laminate (from [4.1]) and (b) a glass/urethane triaxial
braid (from [4.2]). The fiber direction is parallel to the
bands of microcracks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
Figure 4-2. Typical stress-strain response of a polymer composite
when the deviatoricstress in plies is pure shear.
(a) AS4/1895 tape laminate (b) AS4/3501-6 plain weave. . . . . . . . . 4-2
Figure 4-3. Micrograph of a typical kink band in an aligned tow in
an AS4/1895 3D interlock weave . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
Figure 4-4. Schematic of buckling under in-plane compression
following delamination due to impact . . . . . . . . . . . . . . . . . . . . . . . . 4-6
Figure 4-5. Schematic of delamination and shear failure events in
a typical 2D weave. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7
Figure 4-6. Stress-strain curves for plain woven carbon/eopxy laminate.
(a) Unnotched. (b) Notched (d = 4 mm) . . . . . . . . . . . . . . . . . . . . . 4-11
Figure 4-7. Stress-strain data for a 3D interlock weave tested in uniaxial
tension aligned with the stuffers . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-13
Figure 4-8. Stitching bridging a delamination crack in a curved part . . . . . . . . . 4-14
Figure 4-9. Map of failure modes for a curved panel. . . . . . . . . . . . . . . . . . . . . . 4-15
