EnvPERose 0 Report post Posted September 15 The Pressure gauge in an air cylinder reads 1.680 kPA. The cylinder is constructed of a 12-mm rolled steel plate with an internal diameter of 700 mm. The tangential stress (MPa) inside the tank is most nearly: A. 25 B. 50 C. 77 D. 100 The answer provided in the solutions is B. I think it is wrong, should the answer be .05 MPa? Thank you! Share this post Link to post Share on other sites

EnvPERose 0 Report post Posted September 15 The Solution is as follows: Refer to Cylindrical Pressure Vessel in the Mechanics of Materials section of the FE Reference Manual (top left of page 81). The cylinder can be considered thin-walled if t < do/2. In this case, t = 12 mm and ro = do/2 = 362 mm. Thus, Tangential stress = Pi * r / t where r = (ro + ri) /2 do = 700mm (di) + 12 mm + 12 mm = 724 mm => ro = 724 mm/ 2 = 362 mm di = 700 mm = > ri = 700 mm/ 2 = 350 mm r =( 362 mm + 350 mm ) / 2 = 712 mm / 2 = 356 mm Tangential stress = Pi * r / t = 1.680 kPa * 356 mm / 12 mm = 50 kPa Therefore, answer is .050 MPa. (not 50 MPa?) Am I missing something here? Share this post Link to post Share on other sites