A closed-end cylinder is made of 7079-T651 aluminum alloy. The cylinder has an inside diameter D=1000 mm, has a wall thickness h=20 mm, and is subjected to an internal pressure p=6.0 MPa. Determine the length of crack (2a) required to cause fracture at this pressure if plane strain conditions are assumed to be satisfied. The inside of the cylinder is covered with a thin layer of rubber to prevent leakage.

Take KIC=26 MPa m . From Strength of Materials: a closed cylindrical pressure vessel Ïθθ = pr t , Ï zz = pr 2t . You can use the stress intensity factor solution for a flat plate with an internal crack for K1 , since the effect of curvature is negligible. If the crack with length 2a=19.1 mm is circumferential instead of longitudinal for the cylinder, determine the internal pressure that will cause fracture.

Which of the following ziegler nichols tuning methods the response of the controller to a step input should exhibit an s-shaped curve? a)-open loop mode b)-closed loop mode c)-both modes (open & closed) d)-none of the modes (open & closed)

Machinery that is a key part of the process and without which the plant or process cannot function is classifed as: (clo4) a)-critical machinery b)-essential machinery c)-general purpose machinery d)-none of the specified options.

A3-mm-thick panel of aluminum alloy (k 177 w/m-k, c 875 j/kg-k and ? = 2770 kg/m) is finished on both sides with an epoxy coating that must be cured at or above t,-150°c for at least 5 min. the production line for the curing operation involves two steps: (1) heating in a large oven with air at ts,0-175°c and a convection coefficient of h, 40 w/m2. k, and (2) cooling in a large chamber with air at 25°c and a con- vection coefficient of he 10 w/m2.k. the heating portion of the process is conducted over a time interval te which exceeds the ime required to reach 150°c by 5 min (h = r + 300 s). the coating has an emissivity of ? = 0.8, and the temperatures of the oven and chamber walls are 175 and 25°c, respectively. if the panel is placed in the oven at an initial temperature of 25°c and removed from the chamber at a safe-to-touch tempera ture of 37°c, what is the total elapsed time for the two-step curing operation?