Improving the Transient Thermal Fatigue Life of a Gas Turbine Casing by Drilling Stop Holes and Inserting Pins into Them

Document Type : Research Article

Authors

Department of Mechanical Engineering, University of Zanjan, Zanjan, Iran

Abstract

Gas turbines casings are susceptible to cracking at the edge of the eccentric pin hole. This
paper describes the improvement of the transient thermal fatigue life of gas turbines casings through the
application of pins. The repair technology under consideration involved drilling a number of holes in
the gas turbines casing along the crack and inserting pins into them. The crack position and direction
were determined using non-destructive tests. A series of finite element models were developed and
tested in AStM-A395 elastic-perfectly plastic ductile cast iron. In some specimens, holes were drilled
near the crack tips. Pins were inserted into the holes in some cases. Abaqus software finite element
package and Zencrack fracture mechanics code were used for modeling. The efficiency of crack repair
by the installation of pins was investigated along with the effect of the number of pins on crack repair
efficiency. The result shows that the insertion of pins into holes drilled in the vicinity of the crack tips is
an effective method of retarding crack growth in a gas turbine casing.

Keywords

References

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AUT Journal of Mechanical Engineering
Volume 1, Issue 1
June 2017
Pages 67-74

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