PSI - Issue 5

Patrícia C. Raposo et al. / Procedia Structural Integrity 5 (2017) 1097–1101 Patrícia C. Raposo et al. / Structural Integrity Procedia 00 (2017) 000 – 000

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4

(a)

(b)

Fig. 4. Specimens: (a) before the test; (b) after the test (images from: [4]).

2.2.2. Results In Fig. 5 are shown the strength versus displacement results from the tensile tests, being possible to conclude that the eucalyptus wood has a, nearly, linear behaviour between 0.4 MPa and 30 MPa. The rupture of the majority of specimens occurred with a displacement of, approximately, 5mm with the exception of the specimen 3. Table 3 presents the rupture strength results, with a mean value of 65.5 MPa and an associated COV of 6.5%, showing the proximity of the results of the specimens.

0 10 20 30 40 50 60 70 80 90 100

Specimen 1 Specimen 2 Specimen 3 Specimen 4 Specimen 5 Specimen 6

Table 3. Obtained tensile rupture strength.

Specimen Rupture strength (MPa) Mean COV (%) 1 65.44

2 3 4 5 6

63.13 57.08 58.30 61.89 69.14

Strength ( σ ) (MPa)

65.5

6.5

0

1

2

3

4

5

6

Displacement ( δ ) (mm)

Fig. 5. Tensile strength VS displacement curve.

2.3. Compressive strength test

2.3.1. Procedure and equipment The compression test parallel to the fibers was carried out according to the Portuguese standard NP-618 (1973) [7] using specimens with 20 × 20 × 60 3 (height x depth x length) as shows Fig. 6. Were tested 6 specimens. The tests consisted in the application of compressive load, with a velocity of 5 mm/s, in a direction parallel to the fibers, until it broke (Fig. 6 (c)). It was used the same equipment referred in 2.2.1. changing only the setup.

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(b)

(c)

Fig. 6. (a) Dimensions of the specimens (all dimensions in mm); (b) Specimens before the test; Test setup (images from: [3]).