Accession Number:

AD0269596

Title:

STRESS REDISTRIBUTION IN NOTCHED SPECIMENS UNDER CYCLIC STRESS

Descriptive Note:

Corporate Author:

MINNESOTA UNIV MINNEAPOLIS

Personal Author(s):

Report Date:

1961-10-01

Pagination or Media Count:

1.0

Abstract:

Most materials exhibit a change in stress-strain relationship when subject to fatigue stresses. The effect of this change on the stress distribution across the throat of notched plate specimens of mild steel is examined. The strain distribution across the specimens was determined under dynamic conditions for various numbers of cycles. Tests of unnotched specimens were used to obtain the cyclic stress-strain properties for corresponding numbers of cycles, and from these data the stress distribution in the notched specimens was determined. Good agreement was obtained between the integral of the stress distribution curve and the total load on the specimen. Tests in which the strain amplitude at the notch root was held constant revealed a decreasing maximum stress with fatigue cycles. In other tests in which the load amplitude was constant, the maximum stress amplitude decreased with number of fatigue cycles, despite an increasing strain amplitude. In both types of test, the stress concentration factor decreased with increasing average-stress amplitude, and a further decrease occurs with increasing number of fatigue cycles. Author

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Distribution Statement:

APPROVED FOR PUBLIC RELEASE