Fracture analysis of a bolted joint of a large pump frame of a desalination plant

The present paper deals with the fracture analysis of the frame of a very large pump. The complex geometry of the structure as well as loading conditions were responsible of premature fracture failures localized in the neighborhood of the bolted connection between the column pipe and the basement plate. Retrofitting solutions and appropriate countermeasures were proposed after long lasting hydrodynamic and structural analyses that needed to account for very strict operational and time constraints. The fracture strength as well as the vibration behavior of the structure were considered taking advantage of both numerical FE calculations and experimental insitu measurements. The parallel numerical and experimental analyses leaded to a set of modifications of the structure hereunder described in detail. The integration among experimental and theoretical results concurred to obtain a suitable solution for a quite complex case study because it allowed improving aspects related to both the strength and the loading conditions of the structure.