This paper presents a study on loosening of threaded fasteners subjected to dynamic shear loads. A fundamental analysis of loosening reveals that a fastener can loosen at lower loads than previously expected due to localized slip at the contact surfaces. Four di!erent loosening processes of a screw
Three-dimensional finite element analysis of threaded fastener loosening due to dynamic shear load
โ Scribed by N.G. Pai; D.P. Hess
- Publisher
- Elsevier Science
- Year
- 2002
- Tongue
- English
- Weight
- 659 KB
- Volume
- 9
- Category
- Article
- ISSN
- 1350-6307
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โฆ Synopsis
The two most widespread causes of failure of threaded fasteners subjected to dynamic loads are fatigue and vibration induced loosening. This paper presents results of a study on failure of threaded fasteners by vibration induced loosening caused due to dynamic shear loads. Previous experimental work has revealed that fastener loosening occurs as a result of complete or localized slip at the thread and head contact surfaces. A three-dimensional finite element (FE) model is used to study details of four different loosening processes that are characterized by either complete or localized slip at the head and thread contacts. The FE model is found to be capable of adequately modeling factors that influence slip and predicting the different loosening processes. Primary factors that influence slip at fastener contacts are discussed. The results show that loosening can occur at relatively low shear loads due to the process of localized slip.
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