Miscellaneous Steel Structures
StBK Stalbyggnadskontroll has participated in a large number of projects in various countries. Assignments have been performed at locations from Narvik, Norway in the north to Cacuaco, Angola in the south, for clients from Miami, Florida in the west to Helsinki, Finland in the east.
Assignments have concerned steel structures of different kinds - apart from structural steel frames in buildings, steel bridges, overhead crane runway girders and steel chimneys - cranes, masts, conveyors, mechanical structures, trucks, railway waggons for transport of iron ore, trailers and tanks. These assignments have in many cases related to fatigue problems in welded components, where we have special expertise.
An example of assignments related to welded mechanical structures with fatigue problems has concerned railway waggons for the mining company LKAB, for transport of iron ore on the railway line from Kiruna to Lulea in the north of Sweden. StBK has evaluated the fatigue life of the structure on the basis of full-scale stress measurements in critical parts of the welded steel structure.
Stress range spectra have been evaluated from on-track recordings, and the expected fatigue life correlates well with observations of fatigue cracks in critical welds after 2.5 years of service. The results of the investigation should be used to guide corrective actions in existing structures and the conditions for future orders of new waggons.