The dynamic behaviour of slender structures with cross-sectional cracks
1983 (English)In: Journal of the mechanics and physics of solids, ISSN 0022-5096, Vol. 31, no 4, 329-345 p.Article in journal (Refereed) Published
A dynamic model for beams with cross-sectional cracks is discussed. It is shown that a crack can be represented by a consistent, static flexibility matrix. Two different methods for the determination of the flexibility matrix are discussed. If the static stress intensity factors are known, the flexibility matrix can be determined from an integration of these stress intensity factors. Alternatively, static finite element calculations can be used for the determination of the flexibility matrix. Both methods are demonstrated in the present paper. The mathematical model was applied to an edge-cracked cantilevered beam and the eigenfrequencies were determined for different crack lengths and crack positions. These results were compared to experimentally obtained eigenfrequencies. In the experiments, the cracks were modelled by sawing cuts. The theoretical results were, for all crack lengths, in excellent agreement with the experimental data. The dynamic stress intensity factor for a longitudinally vibrating, centrally cracked bar was determined as well. The results compared very well with dynamic finite element calculations. The crack closure effect was experimentally investigated for an edge-cracked beam with a fatigue crack. It was found that the eigenfrequencies decreased, as functions of crack length, at a much slower rate than in the case of an open crack.
Place, publisher, year, edition, pages
1983. Vol. 31, no 4, 329-345 p.
BEAMS AND GIRDERS
IdentifiersURN: urn:nbn:se:kth:diva-25477DOI: 10.1016/0022-5096(83)90003-0OAI: oai:DiVA.org:kth-25477DiVA: diva2:358729
QC 201010252010-10-252010-10-252010-10-25Bibliographically approved