(3) A film on a substrate delaminates from an edge as shown in Figure 2. The thickness of the film prior to delamination is known to be t, and its thickness after delamination is some unknown T. The total distance of the delamination front from the edge is B and the delaminated portion of the film contracts to a length b. Assume the film is very long and does not contract in the out-of-plane direction. Further assume that the material deforms in a way so that it maintains a constant volume. Calculate the three stretch ratios in the delaminated material relative to the global coordinate system shown and calculate the principle Lagrangian strains. Note: Ignore the effect of the slight bend near the edge of the delaminated region. FIGURE 2. X B