Original scientific paper

Model for fatigue lifetime prediction of torsion bars subjected to plastic presetting

Vinko Močilnik ; ERD d.o.o., Engineering, Design & Development, Črneče 186, 2370 Dravograd, Slovenia
Nenad Gubeljak orcid.org/0000-0002-3276-8431 ; University of Maribor, Faculty of Mechanical Engineering, Smetanova ul. 17, 2000 Maribor, Slovenia
Jožef Predan ; University of Maribor, Faculty of Mechanical Engineering, Smetanova ul. 17, 2000 Maribor, Slovenia

Abstract

The torsion presetting of a spring-bar is a common technique for extending the elastic twist-angle and increasing torque, but it reduces fatigue lifetime. Spring-bars are used as shock absorbers in caterpillar machines. Spring-bars, made from high strength fine-grain steel, grade VCN, provide a high level of absorbed energy. Any slight change in the presetting procedure has a strong influence on fatigue-lifetime. Within the same loading range, springs can exhibit low-cyclic or high-cyclic fatigue behavior regarding different presetting levels. A model for fatigue-lifetime and shear-stress levels is proposed on the basis of performed tests. Considering prescribed fatigue tests, it is possible to optimize a spring bar's geometry, in order to survive the required number of cycles.

Keywords

presetting; torsion; spring-bars; fatigue; lifetime; cyclic fatigue; torque; spring steel

Hrčak ID:

75400

URI

https://hrcak.srce.hr/75400

Publication date:

27.12.2011.

Article data in other languages: croatian

Visits: 6.044 *