This preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: SN Diagram for Steel for Problem 62c FIGURE 62c 1 . 10 3 1 . 10 4 1 . 10 5 1 . 10 6 1 . 10 7 1 . 10 8 10 100 1 . 10 3 S' f N ( ) ksi N N 10 3 10 5 , 10 8 .. = 6. Plot the SN curve over the range S' f N ( ) a N b ⋅ return N 10 6 < if S' e otherwise = 5. To draw the SN graph over the range 10 3 <= N <= 10 8 , define a piecewise continuous function. a 194.4 ksi = a S m 10 3 ( 29 b = b 0.0851 = b 1 z log S m S' e ⋅ = 4. Determine the constants a and b from equations (6.10c) and (6.10a). From Table 65, for N = 10 6 , z 3.000 = S' f a N b ⋅ 3. The equation for the SN curve in the HCF region is given by equation (6.10a): S m 108.0 ksi = S m 0.9 S ut ⋅ = 2. Using equation (6.9), calculate the fatigue strength at N = 10 3 cycles. S' e 60.0 ksi = S' e 0.5 S ut ⋅ return S ut 200 ksi ⋅ ≤ if 100 ksi ⋅ otherwise = 1. Using equation (65a), calculate the uncorrected endurance limit. Solution: See Mathcad file P0602a. S ut 120 ksi ⋅ = Tensile strength Given: ksi 10 3 psi ⋅ = Units: Statement: For the strength data in row a in Table P62, calculate the uncorrected endurance limit and draw the strengthlife ( SN ) diagram for the material, assuming it to be steel. PROBLEM 62c SN Diagram for Aluminum for Problem 64c FIGURE 64c 1 . 10 3 1 . 10 4 1 . 10 5 1 . 10 6 1 . 10 7 1 . 10 8 10 100 1 . 10 3 S' f N ( ) ksi N N 10 3 1.0110 5 ⋅ , 10 8 .. = 6. Plot the SN curve over the range S' f N ( ) a N b ⋅ = 5. To draw the SN graph over the range 10 3 <= N <= 10 8 , a 269.58 ksi = a S m 10 3 ( 29 b = b 0.1324 = b 1 z log S m S' f5E8 ⋅ = 4. Determine the constants a and b from equations (6.10c) and (6.10a). From Table 65, for N = 5E8 , z 5.699 = S' f a N b ⋅ 3. The equation for the SN curve in the HCF region is given by equation (6.10a): S m 108.0 ksi = S m 0.9 S ut ⋅ = 2. Using equation (6.9), calculate the fatigue strength at N = 10 3 cycles. S' f5E8 19.0 ksi = S' f5E8 0.4 S ut ⋅ return S ut 48 ksi ⋅ ≤ if 19 ksi ⋅ otherwise = 1. Using equation (65c), calculate the uncorrected fatigue strength at 5E8 cycles. Solution: See Mathcad file P0604a. S ut 120 ksi ⋅ = Tensile strength Given: ksi 10 3 psi ⋅ = Units: Statement: For the strength data in row a in Table P62, calculate the uncorrected fatigue strength at 5E8 cycles and draw the strengthlife ( SN ) diagram for the material, assuming it to be an aluminum alloy. PROBLEM 64c 1. Using equation (65a), calculate the uncorrected endurance limit. S' e 0.5 S ut ⋅ return S ut 200 ksi ⋅ ≤ if 100 ksi ⋅ otherwise = S' e 55.0 ksi = 2. Calculate the endurance limit modification factors for a nonrotating round rod. Load C load 1 return load "bending" if 1 return load "torsion" if 0.7 return load "axial" if = C load 1 = Size d equiv d = C size 0.869 d equiv in 0.097 ⋅ = C size 0.812 = Surface A 1.34 return surface "ground" if 2.70 return surface "machined" if 2.70 return surface "cold_rolled" if...
View
Full
Document
This note was uploaded on 07/23/2011 for the course EML 4501 taught by Professor Staff during the Spring '11 term at UNF.
 Spring '11
 Staff
 Machine Design

Click to edit the document details