Fatigue Life Extension by Crack Repair Using Double Stop-Hole Technique

Majid Reza Ayatollahi, Seyed Mohammad Javad Razavi, Christof Sommitsch, Christian Moser

Research output: Chapter in Book/Report/Conference proceedingConference paperpeer-review


Drilling holes in the vicinity of the crack tip turns the crack into a notch and reduces the
crack tip stress intensity factor. In this paper, a new idea is used in which instead of a single hole,
two symmetric and interconnected holes are drilled at the crack tip. The main concept of double
stop-hole method is to reduce the stress concentration at the edge of stop-holes in the cracked
structural elements. The double stop drill hole method can be used to increase the fatigue life of the
cracked components. The fatigue crack growth retardation is examined using an experimental
investigation coupled with a stress analysis on the efficiency of proposed double stop-holes. The
distance between the hole centers is considered as the main parameter affecting the efficiency of this
method. The results show that the fatigue life extension caused by the double stop-hole method is
significantly more than the conventional single stop-hole method.
Original languageEnglish
Title of host publicationMaterials Science Forum
Place of PublicationSwitzerland
PublisherTrans Tech Publications Ltd.
ISBN (Print)ISSN: 1662-9760
Publication statusPublished - 2017
Event9th International Conference on Processing and Manufacturing of Advanced Materials: Thermec 2016 - Stadthalle Graz, Graz, Austria
Duration: 29 May 20163 Jun 2016


Conference9th International Conference on Processing and Manufacturing of Advanced Materials
Abbreviated titleTHERMEC 2016
Internet address

Fields of Expertise

  • Advanced Materials Science

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