Two thin-walled aluminum (G= 26 GPa) extrusions are to be loaded in simple torsion with T= 900 N-m. Extrusion A is a simple hollow rectangular tube of uniform wall thickness. Extrusion B is identical to extrusion A except that a narrow slit has been cut along the entire length of the structure as shown. Note that for convenience, the given dimensions are to the centerline.

a) (7 pts) Determine the maximum value of shear stress occurring in each extrusion. Use units of MPa. (Neglect stress concentrations).

b) (4 pts) For the closed tube only, determine the rate of twist d?/dz, in units of degrees/meter.

CoursHeroTranscribedText

Transcribed Image Text:

100 m mm 200mm t=5mm SLIT 100 m mm 200mm t=5mm SLIT