Question

thin walled pressure vessel

Thin walled pressure vessel rectangular prism- Word Help Tell me what you want to do ew 1 Norma No Spac. Heading 1 Heading2e Subtitle Suble Em.. Emphasis Intense E... Strong Styles Thin walled pressure vessel rectangular prism An APU battery explodes on a plane with a maximum pressure of 10.9MPa being produced. Aluminium alloy 6061 T6 is used (yield strength 276 MPa, Ultimate tensile strength 310MPa) as its casing to contain the blast. What should be the thickness of the casing wall to contain the blast? bolt locations h 200mm W 300mm L 400m For maintenance requirements the APU has a lid that is bolted to the casing with eight bolts made from AIsI 4340 steel as indicated in Figure 1). The bolts are located at the four corners of the lid and in the middle of the four sides (Figure 1). The diameter of the bolts is 25 mm with a core diameter of 20 mm in the threaded section. The bolts are pre tensioned during assembly to a stress of 75% of the yield strength of the bolt steel to ensure the nut does not come loose during operation. Determine the critical stress situation(s) that have to be considered in the design of the APU Le for the casing as well as the bolts. Explain and justify which loading you are including Criteria: Correct identification of critical stress location and critical stress values based on correct calculation of loads and justified and consistent stress analysis.

Answer 1

Given data: - yield strength sigma_y = 276 MPa ultimate stress sigma_u = 310 MPa pressure P = 10.9 MPa d_b = 25 mm d_c = 20 mm To calculate the pretensioning stress = 0.75 times 276 = 207 MPa Total No. of Bolts = 8 Therefore Bolts are made of steel Therefore Critical stress in the Bolt sigma_c = sigma_P + Internal load sigma_c = 207 + 10 g sigma_c = 217.9 MPa For one Bolt sigma_c = 217.9/8 sigma_c = 27.23 MPa Hence casing are made of alluminium so thickness of thin casing should be sigma times 2(300 + 200)t = P_max (300 times 200 t = 10.9 times 300 times 200/276 times 1000 t = 2.369 mm For the safe design of casing thickness should be more than > 2.369