TPE331/t76 Turboprop Propulsion Engine Durability

Item

Title
TPE331/t76 Turboprop Propulsion Engine Durability
Date
1982
Index Abstract
Coming Soon
Photo Quality
Incomplete
Report Number
AFWAL TR 82-4069
Creator
Wynn, Larry P.
Corporate Author
Garrett Turbine Engine Company
Date Issued
1982-08-01
Extent
176
Identifier
ADA122962
Distribution Classification
1
DTIC Record Exists
No
Distribution Change Authority Correspondence
None
Abstract
This report on retirement-for-cause is based on the Garret TPE331/T76 turboprop engine second-stage turbine wheel. This second-stage turbine wheel is an integrally bladed wheel with continuous rim slots between each blade at the rim. The slot is ended with a circular hole. The slot and hole reduce thermal and centrifugal stresses existing at the heated outer rim and extend turbine low-cycle-fatigue life. This program was planned to develop criteria from examination and analysis of field service wheels that would allow the Air Force to define how much life remained in the wheel with an observed crack. The investigated wheel displayed significant scatter in cycles to initiate a given crack size. This scatter was traceable to the large variation in gran size at the rim of these cast integrally bladed wheels. Crack propagation analysis was able to predict the observed crack-growth rate. However, no correlation between crack initiation and usage could be identified during this program that would aid implementation of retirement-for-cause.
Report Availability
Full text available by request
Provenance
IIT
Type
report