Fatigue behavior of internally ring stiffened tubular joints
- TWI, Cambridge (United Kingdom). Structural Integrity Dept.
The objectives of the work were to determine the applicability of the hot-spot stress concept and existing S-N curves to stiffened joints, and identify modes of fatigue cracking. Ten large scale steel tubular joint test specimens, each with a different configuration of internal ring stiffeners, were tested under either axial brace loading or unbalanced out-of-plane bending. Stress distributions were determined from strain gauges. The mechanism and progression of fatigue cracking was monitored. First cracking was always observed in the chord, although six other modes of cracking were also identified. This included internal cracking in some tests. The hot-spot stress approach was applicable to determination of fatigue life. Existing parametric equations for calculation of stress concentration factors were over-conservative. Based on measured hot-spot stress, the T design S-N Curve was non-conservative for safe prediction of life to through-wall cracking.
- OSTI ID:
- 403642
- Report Number(s):
- CONF-9606279--; ISBN 0-7918-1492-0
- Country of Publication:
- United States
- Language:
- English
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