7. Frequently the S-N curves for steel can be approximated by a straight line between N = 10 and N = 10° cycles when the data are plotted on a log-log scale, as shown in the figure for SAE 4140 steel. This implies S= AN, where a and b are %3D %3D constants. A. Find b for the 4140 steel for a certain part made from 4140 steel (Fig- ure 17.33). B. Fatigue failures occur after 5 years. By what factor would the cyclic stress amplitude have to be reduced to increase the life to 10 years? Assume the number of cycles of importance is proportional to time of service. 700 600

7. Frequently the S-N curves for steel can be approximated by a straight line between N = 10 and N = 10° cycles when the data are plotted on a log-log scale, as shown in the figure for SAE 4140 steel. This implies S= AN, where a and b are %3D %3D constants. A. Find b for the 4140 steel for a certain part made from 4140 steel (Fig- ure 17.33). B. Fatigue failures occur after 5 years. By what factor would the cyclic stress amplitude have to be reduced to increase the life to 10 years? Assume the number of cycles of importance is proportional to time of service. 700 600

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

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