The Impact of Weld Shape on Fatigue Cracking of Eccentric Geometry Laser Hybrid Welds under Bending Load
2010 (English)In: Proc. of the Int. Conf. on Advances in Welding Science and Technology for Construction, Energy and Transportation, AWST 2010, held in Conj. with the 63rd Annual Assembly of IIW 2010, Istanbul, 2010, 253-259 p.Conference paper (Refereed)
A butt joint of two 10 mm thick stainless steel plates, but 5 mm vertically eccentric to each other, was laser hybrid welded. The weld experiences four point bending fatigue load such that the root stress remains compressive. Thus only the stress formation at the top of the weld was studied, both by fatigue testing and by linear elastic fracture mechanics analysis. The location of the peak stress for crack initiation as well as the direction and speed of crack propagation can be well explained. Weld throat depth, weld toe radii and surface roughness compete against each other for determining the peak stress. It was also shown why occasional lack of fusion has only limited impact on the peak stress and fatigue life. Optimization of the laser beam contribution is responsible for full penetration and for avoiding lack of fusion. Optimization of the MIG-process is essential, as governing the top shape. Beside stress analysis including the topography, the propagation of the cracks along surface resolidification ripples was an indicator that surface roughness has essential impact. Several approaches were developed and studied for systematic documentation and generalization of the discovered knowledge.
Place, publisher, year, edition, pages
Istanbul, 2010. 253-259 p.
Crack, Fatigue, FEA, Geometry, Hybrid welding, Laser, Shape
IdentifiersURN: urn:nbn:se:kth:diva-61577ScopusID: 2-s2.0-79952586970ISBN: 978-605614191-1OAI: oai:DiVA.org:kth-61577DiVA: diva2:479385
International Conference on Advances in Welding Science and Technology for Construction, Energy and Transportation, AWST 2010, held in Conjunction with the 63rd Annual Assembly of the International Institute of Welding, IIW 2010; Istanbul; 11 July 2010 through 17 July 2010
QC 201201262012-01-172012-01-172012-01-26Bibliographically approved