An isotropic epoxy resin (𝐸=2𝐺𝑃𝑎, 𝜈=0.3) is reinforced by unidirectional glass fibers (𝐸𝑔𝑙𝑎𝑠𝑠=70𝐺𝑃𝑎), aligned in the 2 direction, such that the fiber composite is transversely isotropic, with the 1-3 plane being the plane of isotropy. The elastic constants of the fiber composite are:

Question

𝐸1=3.3𝐺𝑃𝑎,
𝜈13=0.25
𝐸2=29.2𝐺𝑃𝑎,
𝜈12=0.3
𝐸3=3.3𝐺𝑃𝑎,
𝐺12=1.27𝐺𝑃𝑎
(Note that 𝜈𝑖𝑗=−𝜀𝑗/𝜀𝑖) Give numerical values for all strain components in the corresponding strain matrix for the stress state below.
𝜎=⎡10 5 0 ⎤
⎥5 -20 0 ⎥ 𝑀𝑃𝑎
⎣ 0 0 0⎦

Value for 𝜀1 ?? (It isn’t 3.235*10^(-3))