Problem 2 (30 points): A plate needs to be designed, which will be 3 mm thick (h), 10 mm wide (b), and has 3 mm
diameter (d) transverse hole, as shown in the figure below. The plate is undergoing bending as shown in the figure with a
bending moment of 10 Nm. To manufacture this plate, you are asked to select a material considering tensile yield strength
(Sy) with a safety factor (SF) of 1. 4. No yielding is allowed in the plate or on/around the transverse hole.
Pay attention to units.
(a) (5 points) State your assumptions.
b
M
3.0
2.8
M
2.6
↑
dih = 0
Mc 6M
-
2.4
nom= 1
(b-d)h²
2.2
0.25
K, 2.0
0.5
1.8
1.0
1.6
2.0
1.4
1.2
1.0
0
0.1
0.2
0.3
dib
0.4
0.5
0.6
(b) (5 points) Determine the nominal stress at the hole, onom (in MPa).
(c) (5 points) Determine the stress concentration factor, Kt, at the hole, clearly mark your numbers in the diagram above.
(d) (5 points) Determine the maximum value of stress at the hole, omax (in MPa).
(e) (10 points) Determine the minimum acceptable yield strength (Sy) (in MPa) and find a material that can withstand
the calculated maximum stress, considering a safety factor (SF) of 1.4. No yielding is acceptable at or around the
transverse hole. Provide material type/grade and one sentence statement on the real-world feasibility of your selection.
