PSI - Issue 42

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Miloslav Kepka jr. et al. / Procedia Structural Integrity 42 (2022) 762–768 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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Fig. 2. Examples of details suitable for HFMI method on the left picture (Marquis, 2016).

2. Samples and testing stend Many types of welded joints, thicknesses and base materials were tested. The results of one type of weld and two types of materials will be shown below. The test specimens for fatigue tests for this paper were prepared from two materials: sheet steel S235JR (+ G3 Si1) and S460MC (+ G46 4 M21 4Si1) with a thickness of 15 mm. S235JR steel was chosen for the tests as a representative of commonly used structural steels, and based on the available literature, the application of HFMI should have little benefit here. S460MC steel, on the other hand, was chosen based on the possibility of potential application in the rail industry.

Fig. 3. From left: Clamping before welding; spot welding; intermittent welds; continuous weld.

The shape of the test samples is determined by the options for mounting on the experimental stand. It is a weld of two sheets, one of which forms the base and the other is welded to it using double-sided fillet weld. Sheets were cut on a water saw. In Figures shows the welding procedure. The first step was to clamp the sheets in the position in which they will be welded. In this position, spot welding ("stitching") was performed and then the fixing fixtures were removed. Subsequently, the root layer was created using alternately interrupted fillet welds with a length of 100 mm, which was then supplemented with a continuous weld. In the last step, a covering layer was created and the sheets were welded in the entire length with a double-sided fillet weld of size a8. In addition to the first and last 30 mm welds, 30 mm was also cut in the HFMI approach area. This was done so that these problematic areas did not affect the results of the fatigue tests.