Fatigue behavior of ferritic nodular cast iron at various asymmetry loading cycle

conference paper

English

Walkers Approach of the description of the influence of loading cycle asymmetry in the high-cycle region consists in multiplying by a factor of Pm where P is one of used asymmetry parameters, defined by the quotien of maximum stress and stress amplitude. This approach can be relatively simply generalized also for low-cycle region as shown by the authors last year. Certain difficulty appears for high values parameter P when an unacceptable relation UTS < sigma c Pm (sigma c means fatigue limit) can be obtained. It has a very unpleasant consequence in the High diagram construction: the curve does not cross the UTS value on mean stress axis as asked. The paper proposes a modification which is identical with walkers approach for lower values of asymmetry parameter P and, on the other hand, does not allow to overstep the UTS value for high values of parameter P. The advantage of this modification is best presented in the Haigh diagram.

Fatigue behavior, nodular cast iron, Haigh diagram

KOHOUT, J., VĚCHET, S.

2003

1. 1. 2002

Stockholm, Švédsko

1-901537-32-3

Fatigue 2002

4/5

1

2751

2758

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