PSI - Issue 44

Agnese Natali et al. / Procedia Structural Integrity 44 (2023) 2326–2333 Agnese Natali, Francesco Morelli / Structural Integrity Procedia 00 (2022) 000–000

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3.1. Outcomes from the UNIVERSAL MACHINE TESTS Test results for the tested components are shown in terms of force-displacement curves and failure modes. The diagonal is an open C section, which is named in the following as “Type B”. With regard to the monotonic tension tests (Fig. 6), it can be noticed that the value of bearing resistance in tension decreases with the decrease of the e1 value (so the closer the hole to the free edge of the component is, the lower is the bearing resistance in tension). For the lowest values of e1, tearing of end section is observed. At the same time, the bearing resistance increases with the increase of e1, and after a certain value, bearing resistance is not affected from this parameter anymore, and the only key values are the thickness of the profile and the ultimate strength of the material. With regard to the monotonic compression tests (Fig. 7), it is observed that the value of bearing resistance in compression decreases with the decrease of p1 (so with the distance among the two holes). Local buckling occurs in the plate among the two holes, with closure of the more inner hole for the lower values of p1. This means that bearing resistance in compression can be controlled and limited by the addition of the second inner hole (this allows assuring the over-resistance of the non-dissipative components with respect to bearing resistance both in tension and in compression). With the increase of p1, bearing resistance in compression gets closer to the value of bearing resistance in tension for the higher values of e1, meaning that in any case, with the increase of both e1 and p1, bearing resistance in tension/compression is not affected by these parameters anymore, and the only key parameters remain the thickness of the profile and the ultimate strength of the material.

a

b

Test 1

Test 2

Test 3 Test 4

Test 5

Fig. 6. (a) Force-displacement curves; (b) failure modes of one of the tested diagonals under tension load.

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b

Test 1

Test 2

Test 3

Test 4

Test 5

Fig. 7. (a) Force-displacement curves; (b) failure modes of one of the tested diagonals under compression load.