A flat plate with a hole, shown in Fig. Q2, is made of cast steel with an ultimate tensile strength of u = 490N/mm and yield stress of y = 360 N/mm. The plate is subjected to a cyclic axial force (P) varying with time according to the plot shown in Figure Q2. Assume expected reliability to be 90%, size factor of 0.85, and the design factor of safety is considered as equal to 1.5. a) Calculate the force range, force amplitude, mean force, and force ratio of the cyclic loading. After that please calculate the stress range, stress amplitude and mean stress values at the critical cross section of the plate. [6 marks] b) Determine the corrected endurance limit for the plate. (See Appendix A for the correction factors) [4 marks] c) Determine the thickness 't' of the plate for an infinite life based on the Goodman criteria [8 marks] d) Could you explain how the stress state of the plate would be under the mentioned loading? (e.g., plane stress/plane strain, three-dimensional, symmetry, etc) [4 marks] e) How can you reduce the stress concentrations effects for the plate and improve its fatigue life? Please provide some suggestions [8 marks] a. P P (kN) 300 250 200 150 100 50 0 25 mm 100 mm Figure 1: Thin plate subjected to an axial cyclic loading. Time (S) Figure Q2: Load cycle (load variation) on the plate.