Question 4. Fatigue Failure Prevention

Building upon the results of the load and stress analysis (Q1), determine the minimum factor of safety for fatigue based on the Modified Goodman infinite life fatigue criterion. The shaft rotates at a constant speed, has a constant diameter and is made from a hot-rolled AISI 1006 HR (G10060) steel. You may disregard any stress concentration effects at this stage.

CA AL FA2 dia. da dia. da dia. d 82 Figure 2: Schematic ofthe lathe machine. Table 1. Calculated parameters and dimensions Parameter value 52 200 300 30 35 760 205 76 50 1.9 FB2 1.4 7000 Dim.Parameter equation Unit 45 + P1 200-(1 - P2/10 300 (1 P2/15 30 (1 P2/20) 350 (1 P3/10 400 (1 + P3/10) 1000 - (Li+ L2) 40.(1 + P3/10 500 (1 - P3/10) FB2(1+P3/10) 1.0.(1 P4/15 1000 (1 P4 A1 FA2 FB1 mrad nD CA AL FA2 dia. da dia. da dia. d 82 Figure 2: Schematic ofthe lathe machine. Table 1. Calculated parameters and dimensions Parameter value 52 200 300 30 35 760 205 76 50 1.9 FB2 1.4 7000 Dim.Parameter equation Unit 45 + P1 200-(1 - P2/10 300 (1 P2/15 30 (1 P2/20) 350 (1 P3/10 400 (1 + P3/10) 1000 - (Li+ L2) 40.(1 + P3/10 500 (1 - P3/10) FB2(1+P3/10) 1.0.(1 P4/15 1000 (1 P4 A1 FA2 FB1 mrad nD