Fatigue in a Freight Elevator Axle-Shoulder Fillets

2 Fatigue in a Freight Elevator Axle-Shoulder Fillets 

The axle of a freight elevator, shown in Fig. 7.28, that must sustain a load P — A3 kN is made of Aq50 steel and fine machined in the areas of shoulder fillets. Verily its fatigue strength. The most critical section is the A-A. The maximum bending moment is 

The fatigue limit Sf of Aq50 steel is (see sample problem 1) 200 MPa, the reduced one S f must consider the corrective factors C, and the shoulder fillet. The stress concentration factor for the geometry under investigation is k, — 2.7, as it can be inferred entering the abacus of Fig. 7.26 with pid — 0.02 e djld — 1.5. the 

It can be concluded that the geometry considered is not capable to withstand fatigue for more than 10 cycles. It will be necessary, at least, to increase the shoulder fillet radius that is too small, resulting in a notch factor too high. 

3 Plates Containing Bore Holes-Process Volume Effect 

---