Issue 37

C. M. Sonsino et alii, Frattura ed Integrità Strutturale, 37 (2016) 200-206; DOI: 10.3221/IGF-ESIS.37.26 206 casting technology to perform local dimensional modifications, the mentioned thickness changes do not hinder the realisation of lightweight designs, even if axial loads would be predominant and therefore a local thickness increase or reduction would be linear to the factors 1.10 and 1.25 respectively. These results underline that the Normal (Principal) Stress Hypothesis (NSH) can be applied in its original form without any modifications for “fitting” the obtained experimental results, despite the not very significant limitations. Under- or overestimation of required fatigue lives or local stresses are, in any case, revealed by the durability proof tests, which are mandatory for vehicle safety components [7-9]. A CKNOWLEDGEMENTS he authors acknowledge the Federal Ministry for Economics and Technology (BMWT), Berlin, for funding the research project [5] and the Research Association for Mechanical Engineering FKM/VDMA, Frankfurt, for the support given during the work. Dr. P. Xin and IMAB, TU Clausthal, are acknowledged for their experimental contribution [5]. R EFERENCES [1] Sonsino, C. M., Ziese, J., Fatigue Strength and Applications of Cast Aluminium Alloys with Different Degrees of Porosity, Int. J. Fatigue, 15(2) (1993) 75-84. [2] Sonsino, C. M., Grubisic, V., Mechanics of Fatigue Failures of Cast and Sintered Structural Materials under Multiaxial Stresses, Konstruktion, 37(72) (1985) 7261–269, in German. [3] Sonsino, C. M., Structural Durability of Cast Aluminium Gearbox Housings of Underground Railway Vehicles under Variable Amplitude Loading, Int. J. Fatigue, 27(8) (2005) 944-953. [4] Sonsino, C. M., Influence of Material's Ductility and Local Deformation Mode on Multiaxial Fatigue Response, Int. J. Fatigue, 33(8) (2011) 930-947. [5] Franz, R., Xin, P., Improvement of Fatigue Life Estimation for Multiaxial Loaded Safety Components of Forged Steel and Cast Aluminium by Selection of Appropriate Calculation Algorithms, Final Report – FKM/AiF No. 16059 N/1 (2013), VDMA, Frankfurt/Germany, in German. [6] ANSI/ASTM-E 155-79, Standard Reference Radiographs for Inspection of Aluminium and Magnesium Castings, American Society for Testing and Materials, (1979). [7] Sonsino, C. M., Principles of Variable Amplitude Fatigue Design and Testing, Fatigue Testing and Analysis under Variable Amplitude Loading Conditions, In: McKeighan, P. C. and Ranganathan, N., Editors, ASTM STP, 1439 (2005) 3–23. [8] Grubisic, V., Criteria and Methodology for Lightweight Design of Vehicle Components Subjected to Random Loads, SAE-Paper No. 850367 (1985), Warrendale, PA/USA [9] Sonsino, C. M., Berg, A., Grubisic, V., Structural Durability Proof of Automotive Safety Components – Present State of the Art, SAE-Paper No. 2005-01-0800 (2005), Warrendale, PA/USA [10] Hänel, B., Haibach, E., Seeger, T., Wirthgen, G., Zenner, H., FKM-Guideline – Analytical Strength Assessment of Components in Mech. Eng., VDMA, Frankfurt/Germany, 5th extended Ed., (2007). [11] Sonsino, C. M., Course of SN-Curves Especially in the High-Cycle Fatigue Regime with Regard to Component Design and Safety, Int. J. Fatigue, 29 (2007) 2246-2258. [12] Buxbaum, O., Structural Durability - Safe and Economic Design of Fatigue Components, 2nd Edition, Verlag Stahleisen, Düsseldorf (1992). [13] Haibach, E., Structural Durability – Methods and Data for Calculation, 3rd Ed., VDI-Verlag, Düsseldorf, (2003), in German. [14] Sonsino, C. M., Leightweight Design Chances Using High-Strength Steels, Mat.wiss. u. Werkstofftech. 38(1) (2007) 9- 22. [15] Susmel, L., Sonsino, C. M., Tovo, R., Accuracy of the Modified Wöhler Curve Method Applied Along with the r ref = 1 mm Concept in Estimating Lifetime of Welded Joints Subjected to Multiaxial Fatigue Loading, Int. J. Fatigue 33 (2011) 1075-10. T