PSI - Issue 64

Atsushi Sato et al. / Procedia Structural Integrity 64 (2024) 991–998 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

996

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3. Testing of the angle members 3.1. Specimens and test setup

In order to validate the proposed strength formulas, small-scale experiments using angle-L20×20×3 and angle L25×25×3 are conducted, both of which are of steel grade SS400. The normalized slenderness ratio (represented by λc) was selected to fall within the range of 0.4 to 1.6. Mechanical properties obtained from the coupon tests are summarized in Table 1, while Fig. 6 depicts the experimental setup with spherical supports on both ends. Additionally, an example of a buckled shape is shown.

Table 1. Mechanical properties Cross section of angle

f y (MPa)

f u (MPa)

L20×20×3 L25×25×3

320 361

455 492

a)

b)

Fig. 6 Test setup: a) During loading; b) Buckled shape (L25×25×3,  c =1.35).

3.2. Buckling strength with eccentricity and added-reinforcement In this study, the maximum resistance measured during testing was defined as the buckling strength, N cr . The buckling strengths are summarized in Table 2. They are normalized by the axial yield strength ( N y ), which is 36.1 kN for L20×20×3 and 51.4 kN for L25×25×3.

Table 2a. Buckling strength of L20×20×3  c ( l mm) Ncr (kN) ( N cr / N y ) Single

Reinforced

No.1

No.2

No.1

No.2

0.516 (156) 0.681 (206) 1.01 (306) 1.34 (406) 1.61 (1.61)

20.7 (0.573) 19.7 (0.546) 15.9 (0.440) 9.33 (0.258) 7.61 (0.211)

-

-

-

20.5 (0.568) 17.3 (0.479) 9.64 (0.267) 7.81 (0.216)

22.3 (0.618) 19.8 (0.548) 18.4 (0.510) 18.3 (0.507)

22.1 (0.612) 19.0 (0.526) 18.4 (0.510) 14.8 (0.410)