Life assessment and extension for gas turbine blades

Pertti Auerkari, Jorma Salonen, Juhani Rantala, Sari Mäkinen, Ilkka Karvonen, Heikki Tanttari, Pekka Kangas, Jukka Taattola

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientific

Abstract

Gas turbine blades operate under severe loading conditions, and for satisfactory service must be designed to withstand multiple damage mechanisms. On the other hand, if the assumptions on the future service are sufficiently conservative or actual service conditions more benign than foreseen, there is potential for blade life extension. This generally does not justify fully omitting intermediate inspections, as intervening damage by e.g. overheating or foreign objects is not excluded, and restoring coatings or other repairs could be needed. Nevertheless, a significant extension to the time of final replacement can be possible. In this work, example cases are used to highlight the technical challenges and results of blade life extension. Such aspects include assessment of in-service stress and temperature histories, interpretation of condition assessment, and materials performance. The example cases refer to ex-service blade samples extracted at the time approximately corresponding to the nominal blade life as defined by the engine supplier. Both land based and aircraft turbines are considered, and in spite of the differences in design and service profiles, similarities can be pointed out. The results for the example cases generally suggest significant potential for life extension, for reasons related to the case-specific service histories.
Original languageEnglish
Title of host publicationBaltica VIII
Subtitle of host publicationLife Management and Maintenance for Power Plants
Place of PublicationEspoo
PublisherVTT Technical Research Centre of Finland
Pages117-127
Volume2
ISBN (Electronic)978-951-38-7594-7
ISBN (Print)978-951-38-7593-2
Publication statusPublished - 2010
MoE publication typeB3 Non-refereed article in conference proceedings
EventBALTICA VIII - International Conference on Life Management and Maintenance for Power Plants - Helsinki-Stockholm, Finland
Duration: 18 May 201020 May 2010

Publication series

NameVTT Symposium
PublisherVTT
Number265
ISSN (Print)0357–9387
ISSN (Electronic)1455–0873

Conference

ConferenceBALTICA VIII - International Conference on Life Management and Maintenance for Power Plants
CountryFinland
CityHelsinki-Stockholm
Period18/05/1020/05/10

Fingerprint

Turbomachine blades
Gas turbines
Turbines
Repair
Inspection
Aircraft
Engines
Coatings
Temperature

Cite this

Auerkari, P., Salonen, J., Rantala, J., Mäkinen, S., Karvonen, I., Tanttari, H., ... Taattola, J. (2010). Life assessment and extension for gas turbine blades. In Baltica VIII: Life Management and Maintenance for Power Plants (Vol. 2, pp. 117-127). Espoo: VTT Technical Research Centre of Finland. VTT Symposium, No. 265
Auerkari, Pertti ; Salonen, Jorma ; Rantala, Juhani ; Mäkinen, Sari ; Karvonen, Ilkka ; Tanttari, Heikki ; Kangas, Pekka ; Taattola, Jukka. / Life assessment and extension for gas turbine blades. Baltica VIII: Life Management and Maintenance for Power Plants. Vol. 2 Espoo : VTT Technical Research Centre of Finland, 2010. pp. 117-127 (VTT Symposium; No. 265).
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title = "Life assessment and extension for gas turbine blades",
abstract = "Gas turbine blades operate under severe loading conditions, and for satisfactory service must be designed to withstand multiple damage mechanisms. On the other hand, if the assumptions on the future service are sufficiently conservative or actual service conditions more benign than foreseen, there is potential for blade life extension. This generally does not justify fully omitting intermediate inspections, as intervening damage by e.g. overheating or foreign objects is not excluded, and restoring coatings or other repairs could be needed. Nevertheless, a significant extension to the time of final replacement can be possible. In this work, example cases are used to highlight the technical challenges and results of blade life extension. Such aspects include assessment of in-service stress and temperature histories, interpretation of condition assessment, and materials performance. The example cases refer to ex-service blade samples extracted at the time approximately corresponding to the nominal blade life as defined by the engine supplier. Both land based and aircraft turbines are considered, and in spite of the differences in design and service profiles, similarities can be pointed out. The results for the example cases generally suggest significant potential for life extension, for reasons related to the case-specific service histories.",
author = "Pertti Auerkari and Jorma Salonen and Juhani Rantala and Sari M{\"a}kinen and Ilkka Karvonen and Heikki Tanttari and Pekka Kangas and Jukka Taattola",
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Auerkari, P, Salonen, J, Rantala, J, Mäkinen, S, Karvonen, I, Tanttari, H, Kangas, P & Taattola, J 2010, Life assessment and extension for gas turbine blades. in Baltica VIII: Life Management and Maintenance for Power Plants. vol. 2, VTT Technical Research Centre of Finland, Espoo, VTT Symposium, no. 265, pp. 117-127, BALTICA VIII - International Conference on Life Management and Maintenance for Power Plants, Helsinki-Stockholm, Finland, 18/05/10.

Life assessment and extension for gas turbine blades. / Auerkari, Pertti; Salonen, Jorma; Rantala, Juhani; Mäkinen, Sari; Karvonen, Ilkka; Tanttari, Heikki; Kangas, Pekka; Taattola, Jukka.

Baltica VIII: Life Management and Maintenance for Power Plants. Vol. 2 Espoo : VTT Technical Research Centre of Finland, 2010. p. 117-127 (VTT Symposium; No. 265).

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientific

TY - GEN

T1 - Life assessment and extension for gas turbine blades

AU - Auerkari, Pertti

AU - Salonen, Jorma

AU - Rantala, Juhani

AU - Mäkinen, Sari

AU - Karvonen, Ilkka

AU - Tanttari, Heikki

AU - Kangas, Pekka

AU - Taattola, Jukka

PY - 2010

Y1 - 2010

N2 - Gas turbine blades operate under severe loading conditions, and for satisfactory service must be designed to withstand multiple damage mechanisms. On the other hand, if the assumptions on the future service are sufficiently conservative or actual service conditions more benign than foreseen, there is potential for blade life extension. This generally does not justify fully omitting intermediate inspections, as intervening damage by e.g. overheating or foreign objects is not excluded, and restoring coatings or other repairs could be needed. Nevertheless, a significant extension to the time of final replacement can be possible. In this work, example cases are used to highlight the technical challenges and results of blade life extension. Such aspects include assessment of in-service stress and temperature histories, interpretation of condition assessment, and materials performance. The example cases refer to ex-service blade samples extracted at the time approximately corresponding to the nominal blade life as defined by the engine supplier. Both land based and aircraft turbines are considered, and in spite of the differences in design and service profiles, similarities can be pointed out. The results for the example cases generally suggest significant potential for life extension, for reasons related to the case-specific service histories.

AB - Gas turbine blades operate under severe loading conditions, and for satisfactory service must be designed to withstand multiple damage mechanisms. On the other hand, if the assumptions on the future service are sufficiently conservative or actual service conditions more benign than foreseen, there is potential for blade life extension. This generally does not justify fully omitting intermediate inspections, as intervening damage by e.g. overheating or foreign objects is not excluded, and restoring coatings or other repairs could be needed. Nevertheless, a significant extension to the time of final replacement can be possible. In this work, example cases are used to highlight the technical challenges and results of blade life extension. Such aspects include assessment of in-service stress and temperature histories, interpretation of condition assessment, and materials performance. The example cases refer to ex-service blade samples extracted at the time approximately corresponding to the nominal blade life as defined by the engine supplier. Both land based and aircraft turbines are considered, and in spite of the differences in design and service profiles, similarities can be pointed out. The results for the example cases generally suggest significant potential for life extension, for reasons related to the case-specific service histories.

M3 - Conference article in proceedings

SN - 978-951-38-7593-2

VL - 2

T3 - VTT Symposium

SP - 117

EP - 127

BT - Baltica VIII

PB - VTT Technical Research Centre of Finland

CY - Espoo

ER -

Auerkari P, Salonen J, Rantala J, Mäkinen S, Karvonen I, Tanttari H et al. Life assessment and extension for gas turbine blades. In Baltica VIII: Life Management and Maintenance for Power Plants. Vol. 2. Espoo: VTT Technical Research Centre of Finland. 2010. p. 117-127. (VTT Symposium; No. 265).