PSI - Issue 59

Victor Datsiuk et al. / Procedia Structural Integrity 59 (2024) 583–587 Victor Datsiuk et al./ Structural Integrity Procedia 00 (2019) 000 – 000

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At least 5 samples were cut from different parts of each element and structure. Finally, 150 samples were tested under axial compression along the fibers on the testing machine STM-100 (Fig.2).

Fig. 2. Testing of samples.

3. Results and discussion Based on the test results, the strength parameters of pine wood after prolonged use were determined, including the ultimate compressive strength f c,0,d, and the modulus of elasticity E (Table 1). The results are presented as averaged values. The change in the modulus of elasticity of pine wood was determined using the methodology provided in (Yasniy et al. (2022)).

Table 1. Results of experimental studies on pine wood after prolonged use.

Number of samples

Е , MPa

Number of samples

Е , MPa

Number of samples

Е , MPa

f c,0,d, , МРа

f c,0,d, , МРа

f c,0,d, , МРа

Т, years

Т, years

Т, years

Groups

Moisture level 12%

1 2 3 4 5 1 2 3 4 5

25 25 25 25 25 25 25 25 25 25

5 5 5 5 5 5 5 5 5 5

43.5 12800 50 43.6 12800 50 44.1 12600 50 43.8 12700 50 44.4 12700 50 44.0 12500 50 43.9 12300 50 42.7 12300 50 42.8 12500 50 43.2 12600 50

5 5 5 5 5 5 5 5 5 5

43.3 43.4 43.1 42.7 42.7 41.4 41.6 42.3 41.1 42.0

12500 75 12400 75 12600 75 12500 75 12400 75 12300 75 11900 75 12200 75 12100 75 11900 75

5 5 5 5 5 5 5 5 5 5

42.7 41.8 42.1 42.9 41.6 39.7 40.9 41.1 41.2 40.3

12200 12200 12000 12300 12000 11500 11800 11500 11700 11600

Moisture level 15%

The analysis is conducted on previously investigated pine wood samples with dimensions of 30x30x120mm, which were not in use, corresponding to moisture levels of 12% and 15% (Homon et al. (2023), Janiak et al. (2023)). According to the results of the conducted experiment, it has been established that the ultimate compressive strength and modulus of elasticity of pine wood, during a prolonged service life of 25-75 years with moisture levels