Fraunhofer-Gesellschaft

Publica

Hier finden Sie wissenschaftliche Publikationen aus den Fraunhofer-Instituten.

Fatigue assessment of joints using the local stress field

Schwingfestigkeitsanalyse von Fügeverbindungen basierend auf dem örtlichen Spannungsfeld
 
: Schmidt, Halvar; Baumgartner, Jörg; Melz, Tobias

:

Materialwissenschaft und Werkstofftechnik 46 (2015), Nr.2, S.145-155
ISSN: 0933-5137
Englisch
Zeitschriftenaufsatz
Fraunhofer LBF ()
fatigue assessment; joint; local stress field; material fatigue

Abstract
This paper comprises a brief methodical analysis as well as a practical application of both, the stress averaging approach according to Neuber and the critical distance approach according to Taylor for a fatigue assessment on welded and adhesively bonded thin-walled steel structures. The approaches are discussed and in case of the welded joints compared to the notch stress approach with a reference radius of r(ref) = 0.05 mm, which is usually applied for thin-walled structures. Furthermore, both approaches are applied for an assessment of welded joints and adhesively bonded joints. Using results from fatigue tests, a micro-structural length of * = 0.5 mm could be identified for welds, and * = 2.75 mm for the examined adhesive bonds. The value for steel welds is close to the proposed value of * = 0.4 mm, which was used by Radaj deriving the effective notch radius of r(ref) = 1 mm. For the critical distance approach, a distance of a* = 0.1 mm was derived for welds and a* = 0.9 mm for the examined adhesive bonds. Using the stress averaging or critical distance approach and the identified material values, a reliable fatigue strength assessment can be performed for both welded and adhesively bonded joints.

: http://publica.fraunhofer.de/dokumente/N-336625.html