Goodman and Soderberg Failure Criteriahome.eng.iastate.edu/~gkstarns/me325/goodman.pdf · Given the...
Transcript of Goodman and Soderberg Failure Criteriahome.eng.iastate.edu/~gkstarns/me325/goodman.pdf · Given the...
Goodman and Soderberg Failure Criteria Soderberg
m b
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Goodman
m b
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Sf
Sy Sut
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Goodman Failure Line
Yield Line
Soderberg Failure Line σσm
σσa
What happens if the alternating stress is low and constant, but the mean stress continues to increase ? The ratio of to is the factor of safety − + =
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equation of yield line
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σσm Sut σσm’
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Goodman Failure Line
Load Line
σσa’ Failure
Vary alternating stress and hold mean stress constant
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ratio of to is the factor of safety
σσm
σσa
Sf
Sy Sut
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Goodman Failure Line
Yield Line
σσm’
σσa’
maintain load line ratio, increase alternating and mean stresses σσ
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Goodman Failure Line
Yield Line
σσm
σσa
Given the following information, construct a Goodman Failure Diagram and determine factors of safety considering constant alternating stress and increasing mean stress, constant mean stress and increasing alternating stress, and increasing mean and alternating stress with a constant load line slope. σσa’ = 8.72 ksi σσm’ = 10.5 ksi Sut = 80 ksi Sy = 60 ksi Sf = 21.8 ksi