1. Problem 5.2
A layer of composite with fiber orientation is subjected to
Using stress transformation, compute the safety factor. Use the material data for carbon
epoxy(AS4/3501-6) in Table 1.1. Consider all possible modes of failure.
Solution
From table 1.1
2. Problem 5.3
Compute the rotation matrix for a layer oriented at with respect to the . Use it
to find the transformed reduced stiffness matrix in global coordinates corresponding to
the reduced stiffness matrix in material coordinates computed in Example 5.1.
Solution
From Example 5.1
3. Problem 5.5
A tensile test specimen of the material in Exercise 5.1 is wide, thick, and
long, and is subjected to an axial force of . The fibers are oriented at
with respect to the loading axis.
(a) Compute the in-plane and shear strains in the material coordinate system.
(b) Compute the in-plane and shear strains in the global coordinate system.
(c) Is the cross section under a uniaxial state of strain in the global coordinates? Explain
the origin of each nonzero strain.
Solution
