PSI - Issue 47

Ioan Both et al. / Procedia Structural Integrity 47 (2023) 247–252 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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To assess the lateral deformation of the beam, a comparison between the top and bottom flanges horizontal displacement is presented in Fig. 6. The values are presented versus time due to the difficulty in assessing the values when considering a versus force. A bifurcation of the path is observed at 950 s of the test time, which corresponds to a bending moment of 110kNm. The increased displacement of the top flange indicates the lateral torsional buckling of the beam.

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DH-Bot-Fl DH-Top-Fl M=110kNm

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Lateral displacement[mm]

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Test time[s]

Fig. 6. Lateral displacement evolution for top and bottom flange.

In the support area, where only shear force is present, the specimen showed no sign of deformation, thus the local deformation under the load application point is the result of the stress caused by the bending moment and shear force. No failure of the welding was visually observed. 4. Discussions Processing the data of the experiment, the material and section properties, the resulted moment deflection curve highlights coherent results. Considering the cross-section of the beam, the second moment of area and the section modulus are 2121.4 cm 4 and 212.4 cm 3 , respectively. For the determined yield limit of the 8 mm steel plate, the bending resistance reaches a value of 68.1kNm. In Fig. , this limit is very close to the elastic range of the beam behavior (yellow line). From this point forward, the beam develops plastic strains.

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100 110 120

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Beam response Bifurcation of lateral displacement Resistance Rigidity SLS

Moment [kNm]

Moment [kNm]

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Midspan deflection [mm]

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Midspan deflection [mm]

Fig. 7. Moment-Deflection curve.

Although local deformations occur under the load application point, the weld did not show any signs of failure. Whether lateral torsional buckling or lateral distortional buckling occurs is difficult to assess from experimental test.