Consider a 6061-T651 aluminum plate of thickness 0.5 in, width 10 in with a center crack....

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Consider a 6061-T651 aluminum plate of thickness 0.5 in, width 10 in with a center crack. Plate length is sufficiently long. K = 26 ksiin and = 43 ksi. Find the minimum thickness to satisfy plane strain condition. Is plain strain condition satisfied? (a) Find the failure far-field stress using Failure Assessment Diagram (FAD) approach for the following crack lengths: 2a = 0.20, 1.0, 2.0, 4.0 and 6.0 in. For each case discuss if the failure is dominated by brittle fracture or plastic collapse. What is the trend with increasing crack length? (b) If the plate thickness is increased to 1.2 in, what will be the failure stress for the same crack lengths? Use the FAD diagram below, taken from the book. Use the non-dimensional values of and for x-axis for y-axis. Note that is the nominal stress at collapse (net section stress). Note that there is a typo in the book figure. For x-axis value of 1.0, failure is by plastic collapse, not brittle fracture as shown in the figure. For each crack length choose a far-field stress and find the coordinates and () and then extrapolate the load line to the failure curve to find the far- field failure stress. You will have to print the figure below (preferably on a large scale) to find the intersection of load line with failure curve. 1.2 Failure by brittle fracture 1.0 F Failure curve A Example (See Eq. 3-66) 3 0.8 K, 0.6 0.4 0.2 0 0.2 0.4 Region of no failure Failure by brittle fracture 55 S 0.6 0.8 1.0 1.2 Consider a 6061-T651 aluminum plate of thickness 0.5 in, width 10 in with a center crack. Plate length is sufficiently long. K = 26 ksiin and = 43 ksi. Find the minimum thickness to satisfy plane strain condition. Is plain strain condition satisfied? (a) Find the failure far-field stress using Failure Assessment Diagram (FAD) approach for the following crack lengths: 2a = 0.20, 1.0, 2.0, 4.0 and 6.0 in. For each case discuss if the failure is dominated by brittle fracture or plastic collapse. What is the trend with increasing crack length? (b) If the plate thickness is increased to 1.2 in, what will be the failure stress for the same crack lengths? Use the FAD diagram below, taken from the book. Use the non-dimensional values of and for x-axis for y-axis. Note that is the nominal stress at collapse (net section stress). Note that there is a typo in the book figure. For x-axis value of 1.0, failure is by plastic collapse, not brittle fracture as shown in the figure. For each crack length choose a far-field stress and find the coordinates and () and then extrapolate the load line to the failure curve to find the far- field failure stress. You will have to print the figure below (preferably on a large scale) to find the intersection of load line with failure curve. 1.2 Failure by brittle fracture 1.0 F Failure curve A Example (See Eq. 3-66) 3 0.8 K, 0.6 0.4 0.2 0 0.2 0.4 Region of no failure Failure by brittle fracture 55 S 0.6 0.8 1.0 1.2