PSI - Issue 75

Alberto Visentin et al. / Procedia Structural Integrity 75 (2025) 593–601 Alberto Visentin, Alberto Campagnolo,Vittorio Babini, Giovanni Meneghetti/ Structural Integrity Procedia (2025)

595

3

(Campagnolo et al. 2022), as well as the development of an interactive analysis tool within Ansys® Mechanical to assist finite element analysts in automating fatigue assessments of complex welded structures (Visentin et al. 2022, 2024). It is worth noting that the present formulation of the PSM takes advantage of the linear elastic peak stresses calculated at the weld toes and weld roots of the welded structure, by means of FE models meshed with 2D or 3D solid elements and which must include the geometrical modelling of the weld bead. The adoption of shell finite elements would provide the opportunity to (i) furtherly reduce the size of FE models if compared to solid finite elements and (ii) rapidly analyze large-scale structures. Accordingly, the applicability of the PSM combined with shell finite element models has been investigated in the present work. 2. The PSM applied with shell finite element models A two-step finite element analysis procedure is proposed to apply the PSM in combination with shell FE models. The following procedure is general, however it will be illustrated with reference to welded circular-to-rectangular hollow sections under axial loading, having the geometry of Fig. 1 and Table 1 which has been analysed according to the PSM combined with a global solid FE model as highlighted in Fig. 2 for comparison purposes.

t

(a)

(c)

Brace

Brace

Reinforced shell FEs

T’ = T + 0.5 ∙ z t’ = t + 0.5 ∙ z

z

l br = T/2 + z

z

Crack initiationpoint

t’

A-A

T

(b)

T’

D t

Chord

l ch = t/2 + z

t

Chord

(d)

Reinforced shell FEs

A

A

Brace

T’ = T + s = T + 0.7 ∙ z t’ = t + s = t + 0.7 ∙ z

z

900

B-B

T

B

z

l br = T/2 + z

s

z

t’

T

T’

B

Chord

B

l ch = t/2 + z

360

360

Fig. 1. Geometry of CHS-to-SHS steel welded joints. (a) Location of the experimental crack initiation point and (b) dimensions of the joints (see also Table 1). Schematic representation of the empirical rules proposed by (c) (Meneghetti and Tovo 2002; Meneghetti 2008) and (d) (Eriksson and Lignell 2003) respectively, to account for the weld bead stiffness contribution by locally increasing the thickness of shell elements.