Strength ratio the bottom surface of the laminate

Question

Solve the following problem:

Recompute Problem 1 adjusting for in-situ strength, assuming the transition thickness for this material is tt = 0.6 mm.

Problem 1: Consider a laminate [±45] of the following material:

E₁ = 137.8 GPa

E₂ = 10 GPa

G₁₂ = 5.236 GPa

v₁₂ = 0.3

F_1t = 826.8 MPa

F_1c = 482.3 MPa

F_2t = F_2c = 68.9 MPa

F₆ = 241.15 MPa

And thickness tk = 0.127 mm, subject to Nx = Ny = 1.0 N/mm. Determine the strength ratio R at the bottom surface of the laminate, using the following strength criteria:

(a) Maximum stress,

(b) Maximum strain,

(c) Interacting failure criterion. Do not adjust for in-situ strength. You are allowed to use a computer program to find the stresses but you must present detailed computations of the R values.