PSI - Issue 78

Hadi Monsef Ahmadi et al. / Procedia Structural Integrity 78 (2026) 1745–1752

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Fig. 2. (a) Simply supported web plate; (b) Clamed edges.

3. FEM analysis of Nonlinear static (pushover) of single rigid steel strips with thin steel web plates 3.1. FEM process In this section, a Finite Element Model (FEM) of a single square rigid steel web plate with and without a grid perforation pattern was conducted using ABAQUS software by combining shell (steel web plate) and beam (frame) elements (Monsef Ahmadi et al., 2025). The steel web plate, with dimensions of one meter by one meter and a thickness of 6 mm, was connected to a rigid hinged frame via welded connections. The frame was sufficiently stiff to ensure that yielding would occur within the steel plate itself. Both the frame and the steel plate were assigned elastic material properties with a Young’s modulus of 200 GPa and a Poisson’s ratio of 0.3. The plastic behavior of the steel web plate was defined based on the material properties corresponding to the 6 mm thickness, as detailed in (Monsef Ahmadi et al., 2024) The frame was restrained against out-of-plane deformations at both the top and bottom, and a displacement controlled load was applied to the top beam. As discussed in Section 2, the influence of link width becomes negligible at high opening ratios for both boundary conditions. Therefore, for the perforated configuration, a fixed link width of 50 mm and an opening ratio of 40% were adopted, with grid units having a side length of 200 mm. To minimize mesh sensitivity, a uniform fine mesh with an element size of 25 mm was applied to all models. The specimens were labeled as follows: SPSW-F refers to the solid steel plate without openings; SPSW-G denotes the perforated grid plate; and SPSW-G-123456789 identifies a hybrid configuration where ductile thin steel web plates (1 mm thick) are inserted at selected positions within the rigid grid frame (6 mm). Both the ductile and rigid plates share the same material properties. The numerical suffix indicates the grid locations where ductile infills are applied. E.g., SPSW-G-2468 refers to a perforated steel plate with ductile inserts at positions 2, 4, 6, and 8. The FEM geometry and grid location numbering system are illustrated in Figs. 3a and 3b, respectively.