In a manufacturing process, long aluminum rods of square cross section with d = 25 mm are cooled from an initial temperature of
Ti = 400°C. Which configuration in the sketch should be used to minimize the time needed for the rods to reach a safe‐to‐handle temperature of 60°C when exposed to air in cross flow at V = 8 m/s, T[infinity] = 30°C? What is the required cooling time for the preferred configuration? The emissivity of the rods is ε = 0.10 and the surroundings temperature is Tsur = 20°C.
2 answers:
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Answer:
the minimum component thickness for which the condition of plane strain is valid is 0.005377 m or 5.38 mm
Explanation:
Given the data in the question;
yield strength σ = 690 Mpa
plane strain fracture toughness K = 32 MPa-
minimum component thickness for which the condition of plane strain is valid = ?
Now, for plane strain conditions, the minimum thickness required is expressed as;
t ≥ 2.5( K / σ
)²
so we substitute our values into the formula
t ≥ 2.5( 32 / 690 )²
t ≥ 2.5( 0.0463768 )²
t ≥ 2.5 × 0.0021508
t ≥ 0.005377 m or 5.38 mm
Therefore, the minimum component thickness for which the condition of plane strain is valid is 0.005377 m or 5.38 mm