PSI - Issue 57

Jacopo Pelizzari et al. / Procedia Structural Integrity 57 (2024) 817–823 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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1. Introduction Nodular cast irons are engineering materials widely used for structural applications. This investigation evaluates the static and fatigue properties of specimens made of EN-GJS-500-7. Following previous works [1 – 3], the specimens have been extracted directly from the component geometry tested in the full-scale test to consider the effects of the manufacturing process which strongly affect the mechanical properties of the cast iron. After executing strain controlled fatigue tests, full-scale laboratory tests have been performed on an off-highway axle by applying a typical validation load histogram and the local strain spectrum has been measured using a strain-gauge rosette placed in the area of highest strain. Eventually, the Palmgren-Miner damage index has been evaluated, which is of paramount significance in comparison to the damage index evaluated from real in-field tests. 2. Geometry of the specimens and material characterization The specimens have been extracted from an axle’s trumpet in the positions ind icated in Fig.1.

Specimens extraction location

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Cutting plane

Specimen for strain-controlled fatigue test Specimen for static tensile test

Fig. 1. Geometry of the trumpet of the axle and detail of the area identified for the extraction of the specimens for both static tensile tests and strain-controlled fatigue tests.

In Fig. 1 the specimens for strain-controlled fatigue tests are highlighted in green while the specimen for static tensile test is highlighted in red. T he specimen’s geometry for strain-controlled fatigue tests is described in Fig. 2; the specimen’s geometry for static tensile tests has diameter of the parallel length equal to 5 mm, the fillet radius is 6 mm and the gauge length is 30 mm. The specimen’s geometry of Fig. 2 is according to ISO 12106:2017 [4] and ASTM E606/E606M – 12 [5], while the specimen’s geometry for static tensile tests is according to ISO 6892 -1 2019 [6].