PSI - Issue 18

Rainer Wagener et al. / Procedia Structural Integrity 18 (2019) 490–500 Rainer Wagener, Andreas Maciolek, Heinz Kaufmann/ Structural Integrity Procedia 00 (2019) 000–000

499

10

E

Young’s modulus

I j

Index of the fatigue regime, section of the tri-linear strain life curve

index of the test result cyclic hardening coefficient

K’ k 2

slop of force controlled Wöhler-curves in the longlife fatigue regime

n number of speccimens, sample size cyclic hardening exponent N i number of cycles to crack initiation ���� �� ε f ’ fatigue ductility coefficient total strain amplitude n’

�� empiric standard deviation in stress direction

 a,t  a,e  a,p  a σ f ’

elastic strain amplitude plastic strain amplitude

stress amplitude

fatigue strength coefficient

Acknowledgements Authors are grateful for the support from the Hessen State Ministry for Higher Education, Research and the Arts – Initiative for the Development of Scientific and Economic Excellence (LOEWE) towards conducting the ALLEGRO project. References Basquin, O.H., 1910. The exponential law of endurance tests, Proc. of the ASTM 10 (1910), pp. 625 – 630 Christ, H.-J., 1998. Materialermüdung und Werkstoffmikrostruktur, Hrsg. H.-J. Christ, Werkstoff-Informationsgesellschaft, Frankfurt Coffin, L.F. jr., 1954. A study on the effect of cyclic thermal stresses on a ductile metal, Trans. ASME 76 (1954), pp. 931 – 950 Endo, T. Morrow, J., 1969. Cyclic stress-strain and fatigue behavior of representative aircraft metals, Journal of Materials, JMLSA, 4 (1969), No. 1, pp. 159 – 175 Fatemi, A., Plaiseied, A., Khosrovaneh A. K., Tanner, D., 2005. Application of bi-linear log-log S-N model to strain-controlled fatigue data aluminum alloys and its effect on life predictions, International Journal of Fatigue 27 (2005), pp. 1040 – 1050, DOI: 10.1016/j.ijfatigue.2005.03.003 GE Digital, 2017. Minds + Machines: Meet A Digital Twin, Youtube retrieved 26 July 2017 Hell, M., IMB Watson Internet of Things. 2017. Introduction to Digital Twin: Simple, but detailed, Youtube, retrieved 27 th June 2017 Haibach, E., 1970. Modified linear damage accumulation hypothesis with respect to the decreasing fatigue strength with ongoing damaging, Technische Mitteilungen TM 50 (in German) Landgraf, W.R., Morrow, J.D., Endo, T., 1969. Determination of the cyclic stress-strain curve, Journal of Materials (1969), No. 4, pp. 176-188 Langer, D. F., 1937. Fatigue failure from stress cycles of varying amplitude, Trans. ASME, Journal of Applied Mechanics 4 (1937), No. 4, pp. 160 – 162 Manson, S.S., 1965. Fatigue: A complex subject – some simple approximations, Experimental Mechanics 5 (1965), No. 7, pp. 45 – 87, DOI: 10.1007/BF02321056 Miner, M. A., 1945. Cumulative damage in fatigue, Journal of Applied Mechanics 12 (1945) No. 3, pp. 159 – 164 Möller, B., 2019. Integrale Betrachtung zur Lebensdauerabschätzung von Stumpfnähten im Bereich der Kurzzeitschwingfestigkeit. PhD-Thesis, Technische Universität Darmstadt, Fraunhofer Verlag, Stuttgart, (in print) Morrow, J.D., 1965. Cyclic plastic strain energy and fatigue of metals, ASTM STP 278 (1965), pp. 45 – 87, DOI: 10.1520/STP43764S Palmgren, A., 1924. Fatigue life of bearings (Die Lebensdauer von Kugellagern), VDI-Zeitschrift 58 (1924), pp. 339 – 341 Ramberg, W., Osgood, W.R., 1943. Description of stress-strain curves by three parameters, National Advisory Committee For Aeronautics Technical Note No. 902 Sander, T.H. jr., Mauney, D.A., Staley, J.T., 1977. Strain control fatigue as a tool to interpret fatigue initiation of aluminum alloys, R. I. Jaffee, B. A. Wilcox (Eds.): Fundamental aspects of structural alloy design, Plenum Publishing, New York, USA (1977), DOI: 10.1007/978-1-4684 2421-8_17 Stephens, R.I., Berns, H.D., Chernenkoff, R.A., Indig, R.L., Koh, S.J., Lingenfelser, D.J., 1988. Low cycle fatigue of A356-T6 cast aluminum alloy – a round-robin test program, R. I. Stephens (Ed.): Fatigue and Fracture Toughness of A356-T6 Cast Aluminum Alloy, SAE SP-760, (1988), DOI: 10.4271/881705 Stephens, R. I., Koh, S. K., 1998. Improvements in empirical representation of A356-T6 cast aluminum alloy, In: Stephens, R.I. (editor): Bi-linear log-log elastic strain-life model for A356-T6 cast aluminum alloy round-robin low cycle fatigue data, Fatigue and Fracture Toughness of A356 T6 Cast Aluminum Alloy, SAE SP-760