PSI - Issue 75

Philippe Thibaux et al. / Procedia Structural Integrity 75 (2025) 546–554 P. Thibaux et al. / Structural Integrity Procedia (2025)

552

7

Fig. 5. Measured displacements and applied excitation frequency during the out-of-plane test.

Fig. 6. Cracks identified by DPI. On the left, the left brace with a crack through the brace and water flowing out of the brace. On the right, crack present on the chord side, right connection – no breakthrough crack. 5. Comparison of in-plane and out-of-plane failures The test performed in-plane failed by a breakthrough crack through the brace, while the test performed out-of plane has a failure through the chord. In both cases, multiple failure locations were possible, but only one led to a breakthrough crack. The brace had a thickness of 25mm, while the chord had a thickness of 50mm. Figure 7 compares the number of cycles for crack initiation, breakthrough crack and test interruption (run-out) for the out-of plane (OPB) and in-plane (IPB) bending cases. These points are compared to the standard design curve for a thickness of 25mm, and the mean-curve. The relative difference between crack detection and breakthrough crack is larger in the out-of-plane experiment compared to the in-plane experiment, i.e. the number of cycles between the