PSI - Issue 84

Alessandro Lipari et al. / Procedia Structural Integrity 84 (2026) 1087–1094

1093

section, as occurs for the 45° skewed specimen (Fig. 4b), the numerical difference between the shear force perpendicular to the control section and v E is minimal (-2%). On the other hand, the directions of principal moment align well with the skew angles for all specimens. Secondly, the specimen S75N1Auc could be modeled as a straight slab, given that | v Ed,y / v Ed,x | < 0.25. However, this simplification is disregarded to allow for a full comparison among all the specimens. In averaging shear forces, the two widths each side of the peak are allowed to be different, resulting in a distribution width given by approximately 2 d on the side of the elements towards the slab center and less than 2 d on the side towards the slab edge. The averaged shear forces are those acting perpendicularly to the control section (Fig. 4). Moments are averaged by applying the same criterion.

1.80

1.75

El. 3793

El. 3575

1.75

1.70

El. 3887

El. 3492

1.70

1.65

El. 3888

El. 3409

y [m]

y [m]

1.65

1.60

El. 3981

El. 3326

1.60

1.55

El. 3982

El. 3243

1.55

1.50

Control section

Control section

2.45 2.50 2.55 2.60 2.65 2.70

1.95 2.00 2.05 2.10 2.15 2.20

(a)

(b)

x [m]

x [m]

Fig. 4. Principal shear forces and their components in the elements around the peak for specimens: (a) S60N1Auc, (b) S45N1Auc.

(a)

(b)

Fig. 5. Strains measured on the bottom face of S45N1Auc: (a) measurement; (b) position of LVDTs.

The shear stress resistance τ R,c for all modeled specimens is governed by the minimum shear stress resistance, that is, τ R,c = τ Rc,min . As such, the small differences among specimens are mainly given by the different compressive strengths of each specimen (Table 1). However, when calculating the shear capacity, either using d or a v , but neglecting the cap of τ Rc,min , the correlation between shear resistance and slab skewness observed in the experiments is found. Moreover, the added complexity of replacing d with a v beneficially leads to greater resistance values, although still below τ Rc,min . It can also be noted that for the 15° and 30° skewed specimens, the approach from the new EC2 leads to conservative predictions of the shear capacity (considering the sectional shear determined using a linear finite element model). For S45N1Auc, further analysis of the test results is needed to draw firm conclusions, as indications of flexural failure and reinforcement yielding are observed (Fig. 5). In-depth analysis of the 3D DIC measurements on the bottom is necessary to evaluate the failure mechanism and the potential role of reinforcement yielding in this experiment. Similar observations are made in the analysis report of the experiments, for which the tested-to-predicted ratio of