Q6. A cylindrical vessel 2m internal diameter and 4m long has a wall thickness of 6mm. Strain gauges are installed on the vessel to measure hoop strain (see FIG 6). The Young's Modulus of the Material = 290 GN m^-2 The Yield Stress of the Material = 500 MPa The Questions are (i) What is the maximum allowable pressure if a factor of safety of 4 is to be used? (ii) What pressure would a strain of 40με indicate? For (i) I get: Does this look correct? for part 2, I cannot find the relevant equation to suit the pressure vessel. I have the hoop equation as σ = pr/t Where: p = Pressure r = radius of the vessel at 1000mm t = Thickness of the vessel at 6mm I am aware the strain is represented as a change in length by 0.000040 but I am not sure how to use this in my working out, given the fact I haven't used the Young's modulus of 290 GN m^-2 either. Can anyone help me with this question???