Applied Mechanics Dr. Frishmuth is available to work with you or your engineering staff to provide expert applied mechanics support in areas such as finite element analysis, fracture mechanics evaluations, or failure analysis.
Dr. Ron Frishmuth, P.E. / Consulting Engineer
Fracture Analysis
Finite Element Analysis
Structural Design
Specialized test Equipment Design
Dr. Frishmuth's Resume

Applied Mechanics Engineering Consultant





Frishmuth Consulting Services, LLC
Dr. Ronald Frishmuth, P.E.
P.O. Box 1624
Boerne, TX 78006


Phone: (281) 770-3598
FAX: (210) 549-2541
For further information:


Fracture Analysis

This experimental turbine disk failed during a spin pit test at a speed of 46,000 RPM. Failure investigation revealed that the likely origin of the failure was a defect oriented transverse to the tangential stress in a thin section of the disk below the blade dovetail grooves and near the disk surface.

Material testing, finite element analysis and fracture mechanics calculations were performed. It was demonstrated that a surface defect of semi-circular shape with a surface length of 0.010 inch would be critical at the stress level imposed on the disk at 46,000 RPM.

An investigation into the history of the disk revealed that no fracture mechanics analysis had been done during the design. It was further found that the disk was ultrasonically inspected in the pancake forged condition and passed. However, no additional inspection was apparent in the records. It was concluded that, if fracture analysis had been done during the design phase and careful inspection had been performed during manufacture, this failure could have been avoided.





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