A criminal trial has been conducted to assess the responsibility of the three companies involved in the tragic death of a test engineer: the manufacturer, the material supplier, and the tester. All of them have a certain amount of responsibility, in particular, the investigations conducted on the vessel design show how the general layout of the vessel was not compliant with the current standard design of similar products, characterised by an internally threaded connection between the vessel and the sealing plug.
The fracture analysis localised the point of crack initiation in correspondence of the first thread; the finite element analysis of the vessel highlighted an extreme stress intensification exactly at the crack initiation point, demonstrating a severe mechanical design problem. |