(c) (d)
Figure 10. Effect of loading condition on crack opening profile: (a) at loading (P = Pmax ) and Δa = 0mm, (b) at unloading (P = Pmin ) and Δa = 0mm, (c) at loading (P = Pmax ) and Δa = 2mm and (d) at unloading (P = Pmin ) and Δa = 2mm