Q3. A D400 circular cast iron manhole cover on a weighbridge has a diameter of 600mm and thickness of 50mm. It is fixed (clamped) all around its edge. It was found that a single central force from a HGV being weighed would cause a worst-case loading. For the system: a) State the boundary conditions to solve for the integration constants. b) Determine the integration constants for the loading conditions, c) Calculate the maximum deformation when a central force of 80kN is applied. d) Describe briefly the effect on the maximum deformation and stress distribution, if the manhole cover was simply supported around the edge. [3 marks] [2 marks] [5 marks] [5 marks] For the material assume a Young's Modulus of 168 GNm-2 and Poisson's Ratio of 0.29. [Total Marks Question 3 = 15 Marks]