Drivetrains for turbomachinery used in plant operations generally consist of a centrifugal compressor driven by turbines or electric motors, and may include intermediate speed reducing gearboxes. Each of these drivetrain components require accurate torsional modelling to ensure safe operation. Shaft modelling assumptions for these component sections can significantly alter the location of predicted torsional criticals and responses. One essential modelling assumption is the calculation of effective torsional stiffness in stepped shafts. Industry accepted methods include shaft penetration, the 45 degree rule and FEA approaches. A comparison of the three methods and the torsional impacts on a case study are presented.

This content is only available via PDF.
You do not currently have access to this content.