PSI - Issue 81

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

237

Table 1. Mechanical characteristics of specimens of steel elements of the arch.

І №12

Sheet 10 mm

Profile

∟ 63×6

Ø16

flange

web

Steel grade

S255

S255

S285

A300

S235

Ultimate strength f u , MPa Yield strength f y , MPa

367 244

378 252

434 291

458 329

361 234

as in a conventional beam weakened by an opening. Experimental stresses were measured using strain gauges that were bonded along the height of the half-arch cross-sections (Table 2 and Fig. 4, 5). Comparison of stresses in characteristic cross-sections was carried out: under the action of external load without prestressing; taking into account the influence of strut prestressing itself; and under the action of external load taking into account prestressing.

Table 2. Stress in the upper and lower flanges of the half-arch chord.

Cross-sections

Stress (МPа)

Load case

Flange

1-1

2-2

3-3

4-4

5-5

6-6

7-7

External load

Upper

-83.86 -89.36 -57.90 -55.76

-151.1 -143.4 66.01 64.09 -10.27 -12.67 12.36 14.62 -150.9 78.37 72.98

-141.7 -144.9 35.42 29.92 -19.61 -13.77

-31.47 -36.75 -104.2 -88.48 -27.97 -22.78 30.06 28.05 -42.84 -74.10 -66.98

113.9 97.52 -190.3 -175.1 -32.12 -39.19 25.97 33.15 81.76 77.86 -164.3 -156.0

94.26 81.26 -99.46 -84.80 -19.33 -24.48

-47.54 -49.64 50.40 41.96 56.12 51.68 -70.50

σ T σ E σ T σ E σ T σ E σ T σ E σ T σ E σ T σ E

Lower

Prestressing of the strut

Upper

-0.22 -1.05 2.31

Lower

21.7

4.96 6.97

5.9

22.02

-68.9 8.59 8.50

External load with prestressing

Upper

-84.07 -81.56 -55.59 -52.36

-161.97 -161.31 -59.94

74.93 89.59 -94.50 -76.56

-154.5 57.12 56.95

Lower

-20.10 -17.54

(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. 4. Theoretical 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.