Question
Please answer both the questions for full rating
Find the strain energy release rate for the problem shown in Figure 2.13 wherein a thin elastic film of unit width is peeled from a rigid surface. FIGURE 2.13 A thin film peeled from the rigid substrate. Assume that the bending rigidity of the film is negligible, that L is large, and that the elastic constants of the film are known . The thin film is pulled parallel to the rigid surface as shown in Figure 2.14. Compare the strain energy release rate and the strain energy gained by the film during crack extension for both problems in Figures 2.13 and 2.14. For the problem of Figure 2.13. why is the strain energy released not the same as the strain energy gained by the film ? FIGURE 2.14 A thin film pulled parallel to the surface of the rigid substrate
Explanation / Answer
2.4 E= work done + virtual strain energy= f.s
+1/2fx^2 =P.(L/2)+1/2Pt^2 answer
2.5 strain energy=1/2fx^2=1/2P(L/2)^2 answer