Simulating Fatigue Cracks Growth in Spiral Bevel Gears Part 9 docx

... STUDIES 7.1 Introduction In Chapter 5, fatigue crack growth in the OH-58 spiral bevel pinion under moving, non-proportional loads was predicted. Chapter 6 presented experimental fatigue crack ... presenting data from an OH-58 spiral bevel pinion test. The test was conducted by NASA/GRC. EDM notches were introduced into the root of nine of the pinion teeth to serve as starter...

Ngày tải lên: 11/08/2014, 20:21

... die of spiral bevel gears. The progression of research related to computer analysis of gears has led to the investigation of crack growth in spiral bevel gears. FEM models of spiral bevel gears can ... al,'s [ 199 1] computer program that models the cutting process of spiral bevel gears to determine tooth surface coordinates in three dimensions. Litvin et a...

Ngày tải lên: 11/08/2014, 20:21

... al. 1.63 _ [ 198 41 Au et al. [ 198 1]11 2.56 Air test 3.63 [Proprietary 199 8] Oil test [Proprietary 199 8] _3.36 Fatigue crack growth rate C [ (in/ cycle)/(psi *in 5)]" 1.08e-13 2.72e-17 5.49e-21 1.54e-5 6.19e-20 ... rate C [ (in/ cycle)/(psi *in 5)]" 1.08e-13 2.72e-17 5.49e-21 1.54e-5 6.19e-20 1.23e-5 model parameters. da/dN l° [in/ cycle] 9. 30e-6 2.03e-6 Cycles /inch I...

Ngày tải lên: 11/08/2014, 20:21

... found in aircraft structures [Swift 198 4] [Rudd 198 4] [Miller et al. 199 9], helicopter rotor heads [Irving et al. 199 9], and train rails [Jeong et al. 199 7]. Damage tolerance involves designing ... LABORATORY Simulating Fatigue Crack Growth in Spiral Bevel Gears Lisa E. Spievak, Paul A. Wawrzynek, and Anthony R. Ingraffea Cornell University, Ithaca, New York Prepared und...

Ngày tải lên: 11/08/2014, 20:21

... failures from tooth bending fatigue to spalling to rolling contact fatigue in both spur and spiral bevel gears, The effective case depth is defined as the depth to reach 50 RC. x[Coy et al. 199 5] 2 [Townsend ... Lewicki [ 199 5], would be extremely useful. Savage et al. [ 199 2] used an optimization procedure to design spiral bevel gears using gear tooth bending strength an...

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... l, log(_l) ntrinsic Ul'Ve Figure 3.5: Schematic of fatigue crack growth rate data in Paris regime at different stress ratios collapsing into a single "intrinsic" curve. Using Paris' ... material of interest in this thesis, AISI 93 10 steel, is capable of forming striations [Bhattacharyya et al. 197 9] [Au et al. 198 1] [McElvily et al. 199 6]. Au et al. successfu...

Ngày tải lên: 11/08/2014, 20:21

... scatter in fatigue crack growth rates at different stress ratios in AISI 93 10 steel. Table 4.2 contains the slopes and vertical intercepts from the lines in the figures. In addition, a linear least ... work in [FRANC3D 199 9c], thegainin accuracydoesnotjustify thesignificantincreasein computationaltime. 3.4Chapter Summary This chapter covered theories of LEFM and fatigue per...

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... 10.000 Kmin AK 7.050 2 .95 0 7.000 3.000 5.050 4 .95 0 5.000 5.000 2.550 7.450 2.500 7.500 0.050 9. 950 0.000 10.000 -4 .95 0 t4 .95 0 -5.00 15.000 10.000 -9. 950 19. 950 -10.000 20.000 - 19. 950 29. 950 -20.000 ... R=0.5 _Linear Curve Fit , , , i d , i , , i 10 100 AKef: [ksi *in °'5] Figure 4.7: Intrinsic fatigue crack growth rate for AISI 93 10 in 250 ° oil; I¢ = 1. Table 4.2...

Ngày tải lên: 11/08/2014, 20:21

... under moving load. The KH to K_ ratio also indicates which loading mode is driving the crack growth. Mode I dominant fatigue crack growth is associated with smaller ratios. Qian et al. [ 199 6] studied ... described in Section 3.2.3 can not be used. That method assumed proportional loading, which results in a constant kink angle for the load cycle. Since the ratio is changing in th...

Ngày tải lên: 11/08/2014, 20:21

... is concludedthatthemovingloadmethod'strajectoriesaremoreaccurate. In summary,insightsinto the intricaciesof modelingfatiguecrack growth in threedimensionsweregained. Preliminary stepstoward accuratelymodelingcrack growth ... trajectories in a spiral bevel pinion required expanding the state-of-the-art capabilities and theories for predicting fatigue crack growth rates a...

Ngày tải lên: 11/08/2014, 20:21