Author: Anonymous

I am a teacher and need help creating exam problems. Please recommend more incorrect answers to the following problem but do not explain your logic. A silicone rubber [E = 4.60 MPa, G = 1.60 MPa] wristband has an initial length of 90 mm and a width of 13 mm. If the wearer imparts a normal stress of 400 kPa in the length direction while putting it on, what is the corresponding change in width?

Create 5 variations of the following problem but do not show the answers. At a point subjected to plane stress on the surface of a structural member, the stresses are σx = –5 ksi, σy = –15 ksi, and τxy = 10 ksi. Determine the magnitude of the absolute maximum shear stress at the point.

Create 5 variations of the following problem but do not show the answers. At a point subjected to plane stress on the surface of a gusset plate, the stresses are σx = –24 ksi, σy = 8 ksi, and τxy = –3 ksi. Determine principal stress σp1 at the point.

Create 5 variations of the following problem but do not show the answers. At a point subjected to plane stress on the surface of a backhoe, the stresses are σx = 20 MPa, σy = 70 MPa, and τxy = –60 MPa. Determine the angle θp corresponding to the orientation of the principal planes at the point.

I am a teacher and need help creating exam problems. Please recommend more incorrect answers to the following problem but do not explain your logic. At a point subjected to plane stress on the surface of a compressed air cylinder, the stresses are σx = 20 MPa, σy = 90 MPa, and τxy = –10 MPa. Determine normal stress σn at the point for a counterclockwise coordinate rotation of 13°.

Create 5 variations of the following problem but do not show the answers. Does the orientation of the shear stress arrows in the following image indicate that they are positive or negative?

I am a teacher and need help creating exam problems. Please recommend more incorrect answers to the following problem but do not explain your logic. At a point in a body subjected to plane strain, the strains are εx = –480 με, εy = –400 με, and γxy = –560 μrad. Determine the diameter D of the corresponding in-plane Mohr’s circle.

I am a teacher and need help creating exam problems. Please recommend more incorrect answers to the following problem but do not explain your logic. At a point in a body subjected to plane strain, the strains are εx = –240 με, εy = 20 με, and γxy = 350 μrad. Determine the magnitude of the maximum in-plane shear strain at the point.

I am a teacher and need help creating exam problems. Please recommend more incorrect answers to the following problem but do not explain your logic. At a point subjected to plane stress on the surface of a compressed air cylinder, the stresses are σx = –80 MPa, σy = 40 MPa, and τxy = –80 MPa. Determine shear stress τnt at the point for a counterclockwise coordinate rotation of 52°.

I am a teacher and need help creating exam problems. Please recommend more incorrect answers to the following problem but do not explain your logic. At a point subjected to plane stress on the surface of a compressed air cylinder, the stresses are σx = 27 ksi, σy = 26 ksi, and τxy = –9 ksi. Determine shear stress τnt at the point for a counterclockwise coordinate rotation of 66°.