PSI - Issue 28

J. Serra et al. / Procedia Structural Integrity 28 (2020) 381–392

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Author name / Structural Integrity Procedia 00 (2019) 000–000

1. Introduction Mechanical components under vibrations and fatigue finite element analyses, as well as experimental analyses, have been conducted by several authors to assess the failure causes and to predict the lifetime under those conditions. Infante et al . (2003) conducted failure study in cast steel railway coupling using strain gauge data. Sonsino (2005) developed a methodology to investigate the premature cracking of a cast aluminum railway gearbox housing. Morgado et al. (2008) studied the cracking problems on the driving gearboxes of series 2600 locomotives, using loading data obtained service. Kumar et al. (2014) performed finite element analysis to determine the primary modes of vibration of a truck gearbox. Morgado (2015) performed fatigue life extension study in cast steel railway component using. And developed approaches to study failure in railway components using experimental stress analysis (Morgado, 2016). Hu et al. (2017) performed field tests and finite element analysis to identify the source of cracking of a high-speed train gearbox housing. Zhang et al. (2016) resorted to vibration tests, dynamic analysis, and modal analysis to study the cracking of a high-speed train gearbox housing. To assess the expected life in weld flaws under fatigue loads, several research studies have been conducted, during the last years. Moolwan and Netpu (2013) analyzed the result of weld flaws on the lifetime of a gearbox shaft under fatigue. Zyl and Al-Sahli (2013) studied the effect of a heat affected zone on a sharp corner under fatigue. Darcis et al. (2004) developed a new approach to assess crack growth on welded joints. Ottersböck et al. (2016) studied the consequence of weld flaws on high strength steels under fatigue and Seko et al. tested the effect of different weld defects configurations on the Weibull stress criterion (2016). In this work is presented a structural integrity study of railway component. This mechanical component has the particularity of being manufactured by welding, bending and bolting. Knowing that there are two zones that present structural problems (premature cracking), a vibrational analysis by finite elements is developed. And the membrane and bending stresses are determined through stress linearization of the critical vibration modes for each. A methodology to analysis the critical orientation of crack propagation and its influence in the structural durability of the component is developed. The influence of the flaws’ position and flaws´ geometric parameters in predicted life are also studied. Nomenclature crack depth, half flaw length for through-thickness flaw, flaw height for surface flaw or half height for embedded flaw c half flaw length for surface or embedded flaw, maximum half flaw length in any direction B section thickness in-plane of flaw C, m Paris law’ parameters � finite width correction factor � stress intensity factor due to misalignment �� bending stress concentration factor �� membrane stress concentration factor bulging correction factor � membrane stress intensity magnification factor �� membrane stress intensity magnification factor, in stress concentration zone �� bending stress intensity magnification factor, in stress concentration zone � bending stress intensity magnification factor geometric factor Δ applied stress range Δ stress intensity factor range � , crack propagation direction membrane stress range � bending stress range