Original scientific paper

Compression pre-stress of tubular torsion springs

Vinko Močilnik ; Engineering Biro, Vinko Močilnik s.p., Črneče 186, 2370 Dravograd, Slovenia
Nenad Gubeljak orcid.org/0000-0002-3276-8431 ; Fakulteta za strojništvo, Univerze v Mariboru, Smetanova ulica 17, 2000 Maribor, Slovenia
Jožef Predan ; Fakulteta za strojništvo, Univerze v Mariboru, Smetanova ulica 17, 2000 Maribor, Slovenia
Jože Flašker ; Fakulteta za strojništvo, Univerze v Mariboru, Smetanova ulica 17, 2000 Maribor, Slovenia

Abstract

This paper reports the results of a series of biaxial static compression and torsion experiments performed to evaluate the effects of static compression stress on the fatigue life of those smooth tubes made of high strength spring steel. The fatigue life of biaxial loaded springs depends, among others, on biaxial compression and torsion loading. A high shear loading ratio leads to low-cycle fatigue behaviour rather than high-cycle fatigue, because it was found that a crack was initiated at a local highly deformed area on surface of the specimen. The experimentally obtained results show a significant extension of fatigue strain life as a result of combining axial compression loading with torsion. Cracking behaviour was observed and it was noted that compression pre-stresses contribute to retardation of the fatigue crack initiation process and, consequently, contribute to the extension of fatigue life.

Keywords

fatigue; fatigue life; micro crack; multi axial stress state; pre-stressing; torsion; torsion bar spring; twist angle

Hrčak ID:

59643

URI

https://hrcak.srce.hr/59643

Publication date:

30.9.2010.

Article data in other languages: croatian

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