PSI - Issue 81

Volodymyr Romaniuk et al. / Procedia Structural Integrity 81 (2026) 234–239

238

(a)

(b)

Stresses in cross-sections due to external load

Stresses in cross-sections from prestressing

Stresses in cross-sections due to external load, taking into account prestressing

Fig. 5. Experimental values of stress distribution in the cross-sections of the half-arch along its length: (a) – in the upper flange; (b) – in the lower flange.

Stresses in cross-sections due to external load

Stresses in cross-sections from prestressing

Stresses in cross-sections due to external load, taking into account prestressing

Fig. 6. Character of stress distribution: (a) – in cross-section 2-2; (b) – in cross-section 5-5.

In order to analyze the obtained results, the most stressed cross-sections 2-2 and 5-5 were considered separately (Fig. 6). The obtained data show that the most stressed element is the lower flange of the I-beam in cross-section 5-5, in which the theoretical stress is σ T = -190.3 MPa, that is, at the strut attachment node, which is an intermediate support for the half-arch. The use of strut prestressing allows this cross-section to be unloaded to the stress σ T = -164.3 MPa. At the same time, in the calculated sections from the support part of the arch to the strut, the stresses increase as a result of the prestressing. For example, in section 2-2, the stress in the upper flange of the I-beam is σ T = -151.1MPa and σ T = -161.97MPa, respectively. Despite this, the critical cross-section remains section 5-5, in which the maximum stress decreased by 13.7%. The experimental studies carried out confirmed the theoretical calculations, according to the results of which cross-section 5-5 was also critical, in which the measured maximum stresses as a result of the strut prestressing decreased by 11.5%. By comparing theoretical and experimental results, it was found that the deviation of experimental stress values from theoretical ones for an arch without prestressing was 5.3% for the upper flange and 6.8% for the lower flange. In the case of prestressing this value was 4.3% and 5.2%, respectively. For an arch with prestressing the deviation was 5.8% for the upper flange and 5.9% for the lower flange.