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A comparative analysis of accelerated methods for fatigue life and reliability prediction of machine parts under variable loading
Int. J. Fatigue Vol. 18, No. 7, pp. 507-51 I, 1996 Copyright © 1996. Published by Elsevier Science Limited Printed in Great Britain. All rights reserved 0102-1 ! 23/96/$15.00
ELSEVIER
S0142-1123(96)00005-9
Fatigue Abstracts This section contains abstracts of selected articles, technical reports, dissertations and patents concerned with fatigue. It is prepared in collaboration with Materials Information, a joint service of The Institute of Materials and ASM International. Readers wishing to obtain the full text of articles abstracted here should contact either: The Institute of Materials, 1 Carlton House Terrace, London SW1Y 5DB, UK, or: ASM International, Metals Park, OH 44073, USA (not International Journal of Fatigue). The fees charged for photocopying articles are £7.00 for the first ten pages and £3.00 per additional ten pages (UK office), or $10.00 for the first ten pages and $4.00 per additional ten pages (US office).
Low cycle fatigue behavior of a SiCp reinforced aluminum matrix composite at ambient and elevated temperature Han, N.L., Wang, Z.G. and Sun, L.Z. Scripta Metall. Mater. (1995) 32 (11), 1739-1745
A comparative analysis of accelerated methods for fatigue life and
reliability prediction of machine parts under variable loading Staevski, K. and Chankov, D. J. Mater. Sci. Technol. (Bulgaria) (1995) 3 (1), 30-39 A method for fatigue life prediction is presented and compared with the widely used Serensen-Kogaev damage accumulation rule. The method assumes the variable and service loading and is based on the loading spectrum shape coefficient and the mechanical properties of the material. Application is illustrated by example of a safety shaft under torsional loading. Graphs, 15 ref.
Cyclic stress response, plastic strain-life behavior, and fracture behavior of a SiC particle reinforced aluminium matrix composite were investigated by lowcycle fatigue test. A 20 vol% SiCp/A1 composite was subjected to a low cycle fatigue test under a fully reversed plastic strain control in air at 298 and 441 K. The frequency was 0.03 Hz for the first 10 cycles and was changed to 0.125 Hz for the rest of the fatigue life. Observations indicated initial cyclic hardening, cyclic stability and second hardening at ambient temperature. The cyclic stress response characteristics of the composite were found to be different from its unreinforced matrix at room temperature. A decrease in fatigue endurance due to a rise in test temperature was observed. Graphs, photomicrographs, 12 ref.
The effect of the manufacturing test load on the fatigue of hoist chains Abolfathi, E., Modlen, G.F., Webster, P.J. and Mills, G. Proc. Inst. Mech. Engng. B, J. Engng. Manuf. (1995) 209 (B2), 133-139 The effects of the plastic deformation resulting from the 'calibration' (i.e. the manufacturing test load) of high tensile steel chains are discussed in terms of finite-element analyses and determination of the residual stresses by neutrondiffraction measurements. The fatigue strength of the chains and the compressive residual stresses produced near a fatigue crack initiation site both increased with increase of the calibration load, and reduction of the mean stress and the stress amplitude during fatigue loading was also a joint effect of the calibration. Graphs, 16 ref.
Damage evolution of angle-ply SCS-6/Ti composites under static and fatigue loading Wang, P.C., Jeng, S.M., Chiu, H.-P. and Yang, J.-M. J. Mater. Sci. (1995) 30 (7), 1818-1826 The effect of fibre orientation and laminate stacking sequence on the tensile and fatigue behaviour of SCS-6/Ti-15-3 composites was investigated. The laminates used in this study were: (90°) 6, (0°/plus/minus 45°)s, (0)90°)s and (90°/plus/minus 45°)s. The initiation and progression of microstructural damage at various stress levels was thoroughly characterized. It was found that fatigue life at high applied stresses was controlled by fibre fracture; progressive damage involving fibre fracture, interfacial debonding and matrix cracking became dominant at low applied stresses. Observation of the damage mechanisms in the angle-ply laminates under cyclic loading suggests that increasing the fibre-matrix bonding strength may improve the load carrying capability and fatigue life of laminates containing off-axis plies. Graphs, photomicrographs, 12 ref.
Laser induced shock waves as surface treatment for 7075-T7351 aluminium alloy Peyre, P., Merrien, P., Lieurade, H.P. and Fabbro, R. Surf. Engng. (1995) 11 (1), 47-52 A novel mechanical surface treatment using laser induced shock waves has been applied to the wrought aerospace A1 alloy 7075-T7351 to improve its fatigue behaviour. The optimization of the shock parameters and mechanical effects produced by the treatment have been investigated and fatigue performance is compared with that of conventionally shot peened specimens. It is shown that use of a one-dimensional Lagrangian hydrodynamic shock wave analysis code allows the attenuation of shock waves to be simulated and the depth of the plastically affected zone to be predicted. An analytical model developed to predict residual stress levels gave good agreement with experimental values. The fatigue limit of laser shocked specimens was found to be higher than that following shot peening. This large increase (22%) appeared to result from the high levels of residual stress and the greater extent of the stress field in the laser treated specimens and, most importantly, from the preservation of the surface condition. All these factors greatly increased the duration of the crack initiation stage of fatigue, as was confirmed by a.c. potential drop measurements. Graphs, 8 ref.
Effect of fiber coating on the fracture and fatigue resistance of SCS6/Ti3Ai composites Yang, J.-M. and Chiu, H.-P. Acta Metall. Mater. (1995) 43 (7), 2581-2587 The effect of a Ag/Ta coating on the fracture resistance of a notched SCS-6 fiber-reinforced Ti3AI matrix composite under both static and fatigue loading was investigated. The crack propagation patterns and damage mechanisms under various loading conditions were characterized and compared with its uncoated composite counterparts. The results show that the Ag/Ta-coated composites exhibit a typical mode-I failure pattern under both static and fatigue loading, while mixed mode-I and -II failure patterns were observed in the uncoated SCS-6/Ti-25-10 composite. Under fatigue loading, crack propagation was arrested at stress intensity levels up to 34 and 45 MPa m ~/2 for Ag/Tacoated and uncoated SCS-6/Ti-25-10 composites, respectively. Localized interracial debonding, matrix cracking the fiber bridging in the crack wake were the responsible damage mechanisms for the Ag/Ta-coated SCS-6/Ti-25l0 composite. Extensive interracial dcbonding, crack splitting and branching, however, were found to be the dominant mechanisms in the uncoated SCS-6/Ti25-10 composite. Modifications of interracial bond strength and morphology so as to improve the mechanical properties of the Ag/Ta-coated SCS-6/Ti-25-10 composite can be achieved by thermal exposure at 800°C for up to 200 h. Graphs, photomicrographs, 20 ref.
Effects of gap filler and brazing temperature on fracture and fatigue of wide-gap brazed joints Yu, Y.H. and Lai, M.O. J. Mater. Sci. (1995) 30 (8), 2101-2107 The influence of gap filler content on the fracture, fatigue crack initiation and propagation of AISI 316 stainless steel wide-gap brazed with nickel-based filler metal has been investigated. The brazed joints were found to consist of eutectic, intermetallic compound and solid solution. The volume of solid solution was observed to depend on the gap filler content and brazing temperature. Tensile tests with an extra small strain gauge bonded at the centre of the joints showed that the strength and elongation of the brazed joints increased with brazing temperature, and the addition of gap filler was able to improve
507
ELSEVIER
S0142-1123(96)00005-9
Fatigue Abstracts This section contains abstracts of selected articles, technical reports, dissertations and patents concerned with fatigue. It is prepared in collaboration with Materials Information, a joint service of The Institute of Materials and ASM International. Readers wishing to obtain the full text of articles abstracted here should contact either: The Institute of Materials, 1 Carlton House Terrace, London SW1Y 5DB, UK, or: ASM International, Metals Park, OH 44073, USA (not International Journal of Fatigue). The fees charged for photocopying articles are £7.00 for the first ten pages and £3.00 per additional ten pages (UK office), or $10.00 for the first ten pages and $4.00 per additional ten pages (US office).
Low cycle fatigue behavior of a SiCp reinforced aluminum matrix composite at ambient and elevated temperature Han, N.L., Wang, Z.G. and Sun, L.Z. Scripta Metall. Mater. (1995) 32 (11), 1739-1745
A comparative analysis of accelerated methods for fatigue life and
reliability prediction of machine parts under variable loading Staevski, K. and Chankov, D. J. Mater. Sci. Technol. (Bulgaria) (1995) 3 (1), 30-39 A method for fatigue life prediction is presented and compared with the widely used Serensen-Kogaev damage accumulation rule. The method assumes the variable and service loading and is based on the loading spectrum shape coefficient and the mechanical properties of the material. Application is illustrated by example of a safety shaft under torsional loading. Graphs, 15 ref.
Cyclic stress response, plastic strain-life behavior, and fracture behavior of a SiC particle reinforced aluminium matrix composite were investigated by lowcycle fatigue test. A 20 vol% SiCp/A1 composite was subjected to a low cycle fatigue test under a fully reversed plastic strain control in air at 298 and 441 K. The frequency was 0.03 Hz for the first 10 cycles and was changed to 0.125 Hz for the rest of the fatigue life. Observations indicated initial cyclic hardening, cyclic stability and second hardening at ambient temperature. The cyclic stress response characteristics of the composite were found to be different from its unreinforced matrix at room temperature. A decrease in fatigue endurance due to a rise in test temperature was observed. Graphs, photomicrographs, 12 ref.
The effect of the manufacturing test load on the fatigue of hoist chains Abolfathi, E., Modlen, G.F., Webster, P.J. and Mills, G. Proc. Inst. Mech. Engng. B, J. Engng. Manuf. (1995) 209 (B2), 133-139 The effects of the plastic deformation resulting from the 'calibration' (i.e. the manufacturing test load) of high tensile steel chains are discussed in terms of finite-element analyses and determination of the residual stresses by neutrondiffraction measurements. The fatigue strength of the chains and the compressive residual stresses produced near a fatigue crack initiation site both increased with increase of the calibration load, and reduction of the mean stress and the stress amplitude during fatigue loading was also a joint effect of the calibration. Graphs, 16 ref.
Damage evolution of angle-ply SCS-6/Ti composites under static and fatigue loading Wang, P.C., Jeng, S.M., Chiu, H.-P. and Yang, J.-M. J. Mater. Sci. (1995) 30 (7), 1818-1826 The effect of fibre orientation and laminate stacking sequence on the tensile and fatigue behaviour of SCS-6/Ti-15-3 composites was investigated. The laminates used in this study were: (90°) 6, (0°/plus/minus 45°)s, (0)90°)s and (90°/plus/minus 45°)s. The initiation and progression of microstructural damage at various stress levels was thoroughly characterized. It was found that fatigue life at high applied stresses was controlled by fibre fracture; progressive damage involving fibre fracture, interfacial debonding and matrix cracking became dominant at low applied stresses. Observation of the damage mechanisms in the angle-ply laminates under cyclic loading suggests that increasing the fibre-matrix bonding strength may improve the load carrying capability and fatigue life of laminates containing off-axis plies. Graphs, photomicrographs, 12 ref.
Laser induced shock waves as surface treatment for 7075-T7351 aluminium alloy Peyre, P., Merrien, P., Lieurade, H.P. and Fabbro, R. Surf. Engng. (1995) 11 (1), 47-52 A novel mechanical surface treatment using laser induced shock waves has been applied to the wrought aerospace A1 alloy 7075-T7351 to improve its fatigue behaviour. The optimization of the shock parameters and mechanical effects produced by the treatment have been investigated and fatigue performance is compared with that of conventionally shot peened specimens. It is shown that use of a one-dimensional Lagrangian hydrodynamic shock wave analysis code allows the attenuation of shock waves to be simulated and the depth of the plastically affected zone to be predicted. An analytical model developed to predict residual stress levels gave good agreement with experimental values. The fatigue limit of laser shocked specimens was found to be higher than that following shot peening. This large increase (22%) appeared to result from the high levels of residual stress and the greater extent of the stress field in the laser treated specimens and, most importantly, from the preservation of the surface condition. All these factors greatly increased the duration of the crack initiation stage of fatigue, as was confirmed by a.c. potential drop measurements. Graphs, 8 ref.
Effect of fiber coating on the fracture and fatigue resistance of SCS6/Ti3Ai composites Yang, J.-M. and Chiu, H.-P. Acta Metall. Mater. (1995) 43 (7), 2581-2587 The effect of a Ag/Ta coating on the fracture resistance of a notched SCS-6 fiber-reinforced Ti3AI matrix composite under both static and fatigue loading was investigated. The crack propagation patterns and damage mechanisms under various loading conditions were characterized and compared with its uncoated composite counterparts. The results show that the Ag/Ta-coated composites exhibit a typical mode-I failure pattern under both static and fatigue loading, while mixed mode-I and -II failure patterns were observed in the uncoated SCS-6/Ti-25-10 composite. Under fatigue loading, crack propagation was arrested at stress intensity levels up to 34 and 45 MPa m ~/2 for Ag/Tacoated and uncoated SCS-6/Ti-25-10 composites, respectively. Localized interracial debonding, matrix cracking the fiber bridging in the crack wake were the responsible damage mechanisms for the Ag/Ta-coated SCS-6/Ti-25l0 composite. Extensive interracial dcbonding, crack splitting and branching, however, were found to be the dominant mechanisms in the uncoated SCS-6/Ti25-10 composite. Modifications of interracial bond strength and morphology so as to improve the mechanical properties of the Ag/Ta-coated SCS-6/Ti-25-10 composite can be achieved by thermal exposure at 800°C for up to 200 h. Graphs, photomicrographs, 20 ref.
Effects of gap filler and brazing temperature on fracture and fatigue of wide-gap brazed joints Yu, Y.H. and Lai, M.O. J. Mater. Sci. (1995) 30 (8), 2101-2107 The influence of gap filler content on the fracture, fatigue crack initiation and propagation of AISI 316 stainless steel wide-gap brazed with nickel-based filler metal has been investigated. The brazed joints were found to consist of eutectic, intermetallic compound and solid solution. The volume of solid solution was observed to depend on the gap filler content and brazing temperature. Tensile tests with an extra small strain gauge bonded at the centre of the joints showed that the strength and elongation of the brazed joints increased with brazing temperature, and the addition of gap filler was able to improve
507