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A computational model for determination of service life of gears. (English) Zbl 1139.74442
Summary: A computational model for the determination of the service life of gears in regard to bending fatigue in a gear tooth root is presented. The fatigue process leading to tooth breakage is divided into crack initiation and crack propagation period. The strain-life method in the framework of the FEM-method has been used to determine the number of stress cycles $$N_i$$ required for the fatigue crack initiation, where it is assumed that the crack is initiated at the point of the largest stresses in a gear tooth root. The simple Paris equation is then used for the further simulation of the fatigue crack growth. The functional relationship between the stress intensity factor and crack length $$K=f(a)$$, which is needed for determination of the required number of loading cycles $$N_p$$ for a crack propagation from the initial to the critical length, is obtained using displacement correlation method in the framework of the FEM-method. The total number of stress cycles $$N$$ for the final failure to occur is then a sum of $$N_i$$ and $$N_p$$. The model is used for determination of service life of real spur gear made from through-hardened steel 42CrMo4, where required material parameters have been determined previously by the appropriate test specimens.

##### MSC:
 74S05 Finite element methods applied to problems in solid mechanics 74R10 Brittle fracture
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