Model for fatigue lifetime prediction of torsion bars subjected to plastic presettingMočilnik, Vinko (Avtor) Gubeljak, Nenad (Avtor) Predan, Jožef (Avtor) presettingtorsionspring-barsfatiguelifetimecyclic fatiguetorquespring steelThe 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.20112012-06-01 08:40:06Znanstveno delo26929ISSN: 1330-3651UDK: 620.172/.176:669.14-272OceCobissID: 15346181COBISS_ID: 15655446ISSN pri članku: 1330-3651NUK URN: URN:SI:UM:DK:GFSVKNWMsl