PSI - Issue 46

Robert Basan et al. / Procedia Structural Integrity 46 (2023) 62–67 Robert Basan et al. / Structural Integrity Procedia 00 (2019) 000–000

65

4

Significant number of estimation methods enabling determination of cyclic stress-strain and strain-life fatigue parameters based on monotonic and other material have been proposed in the literature such as Manson (1965), Bäumel and Seeger (1990) or Roessle and Fatemi (2000). New ones are continually and intensively being developed - especially the ones based on artificial neural networks and other machine-learning based approaches and models since they enable inclusion of more input variables i.e. monotonic properties and modelling of much more complex relations among monotonic and cyclic/fatigue parameters than is possible using conventional approaches. However, for the practical applications and purposes, models using less input parameters are often more advantageous since number of monotonic properties and other material information based on which estimation is to be performed are not always available nor easily obtainable. In this paper, approach to estimation previously proposed in Basan et al. (2010) and related expressions (2–5) and developed in Basan et al. (2015), Basan and Marohnić (2019) for estimation of Basquin-Coffin-Manson fatigue parameters of low-alloy steel 42CrMo4 are used. Estimation expressions use Brinell hardness as the principal input variable and specific feature is that individual fatigue parameters are not treated independently.

HB HB          12,59 12981 4 2

   

  f

5,919

b

(2)

10



E

1

   

2

  

HB

HB

(3)

6,3

b







31,056 26781

2

   

   

HB

HB

   4

6,403

c





1951,7 132520

(4)

  10 

f

1

   

2 HB HB 356 328103

  

(5)

1,955

c

 

 

3. Analysis and results For the evaluation of the applicability of fatigue parameters estimation method(s) for determination of fatigue lives of gear teeth flanks subjected to repeating rolling-sliding contact loading, the results of an extensive experimental study of numerous gear pairs by Niemann and Bötsch (1966) were used. In the study, number of gear pairs for which main gearing parameters are given in Table 1., made of differently quenched and tempered low-alloy steel 42CrMo4 were tested. Information on material condition of each gear pair i.e. hardness after the heat treatment as well as operating conditions are given in Table 2. Further details are available in the original reference.

Table 1. Geometrical parameters of analyzed gear pairs. Parameter

Pinion

Wheel

normal module, m n

3 mm

normal pressure angle,  n

20 

23

38

number of teeth, z 1,2

0

0

profile shift coefficients, x 1,2

facewidth, b 1,2

20 mm

20 mm

1,65

transverse contact ratio,  

center distance, a

91,5 mm