A long and thin circuit interconnect of thickness t=0.5mm is to be made from a unidirectional glass/epoxy composite material (E1=60 GPa, E2=10 GPa, 12= and G12=10
GPa). If the interconnect is subjected to a biaxial normal stress (in the fiber direction and its perpendicular direction) of 20MPa:
Calculate the state of strain (20 points).
Calculate the state of strain at 45° with the fiber direction (20 points).
Determine the load exerted in the circuit interconnect (10 points).
Calculate the state of stress at 45° with the fiber direction (20 points).
A thin rectangular roof is made of a fiber reinforced polymeric composite. The composite is comprised of 10 unidirectional laminae with a total thickness t=2 mm. The
fibers are aligned with the long side of the roof. The fiber and matrix phase properties are E1f=300 GPa; Em=3 GPa; Vf=0.7; and the lamina properties are E2=8 GPa,
12= and G12=6 GPa. The roof is subjected to a uniform normal stress of 100MPa in the fiber direction.
Determine the complete set of properties of the composite lamina (10 points).
Calculate the state of strain in the system of coordinates where the fiber direction is a coordinate axis (25 points).
Calculate the normal strain at 30 with the fiber direction (15 points).
