PSI - Issue 8

Francesca Curà et al. / Procedia Structural Integrity 8 (2018) 204–211 Author name / Structural Integrity Procedia 00 (2017) 000 – 000

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Fig. 7. Example of numerical results: m isaligned (10’ ), 700Nm.

Fig. 8. Example of experimental results (1x10 6 cycles): aligned (left); misaligned (right).

4 Conclusions The present paper focused on a new methodology to design a representative test specimen for wear damage characterisation in spline couplings. This methodology has been developed by means of the progressively tuning of influence parameters chosen to this aim. These parameters are, under the hypothesis of equal friction coefficient, the hertzian pressure due to the load entity (torque) and the corresponding slidings. The hertzian pressure, mean and maximum, as a function of the applied torque, has been tuned by varying the teeth microgeometries, crowning radius and involute profile. Slidings have been calculated and perfected in order to make equivalent the fatigue damage due to the teeth elasticity to that coming from misaligned conditions between shaft and hub. The shape of the elliptical contact area, that is the ratio between half-axis, and its position along the length width and respect to the involute profile have been also take into account: this aspects is particularly important referring to the actual behaviour of the component. Furthermore, another main aspect is the position of the contact area, substantially centred respect to the length width in aligned conditions and a little shifted in misaligned ones, but generally corresponding to the pitch diameter zone. Following these directions, the established target for the design of an isodamage specimen has been substantially reached from two points of view.