Page 222 - Mechanics Analysis Composite Materials
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Chapter 4. Mechanics of a composite layer 207
w
Fig. 4.79. A composite leading edge of an aeroplane wing made of carbon fabric by lay-up method.
Courtesy of CRISM.
Fig. 4.80. Unit cell of a fabric structure.
structure is shown the warp (lengthwise) and fill (crosswise) yarns forming the fabric
make angle a 2 0 with the plane of the fabric layer.
To demonstrate how this angle influences material stiffness, consider tension
of the structure shown in Fig. 4.80 in the warp direction. Apparent modulus of
elasticity can be expressed as
E,A, = EfAf + E,A, , (4.165)
where A, = h(2tl + t2) is the apparent cross-sectional area and
h h
(2tl
Af = ; + t2), A, = Z(4tl + t2)
L
are the areas of the fill and warp yarns in the cross section. Substitution into
Eq. (4.165) yields