Transverse shear stiffness of corrugated core steel sandwich panels with dual weld lines

Artikel i vetenskaplig tidskrift, 2017

Advances in the field of laser welding have recently enabled the commercial production of all-steel sandwich panels with a continuous and robust connection between the core and the face plates, even for plate thicknesses over 10 mm. This allows for the application of the high-performance steel sandwich panel in several fields, such as civil structures. In this paper, an analytical model is presented to determine the transverse shear stiffness of corrugated core steel sandwich panels with dual weld lines. The derivation is based on the direct stiffness method (DSM). At the welded connection between the core and the faces, a rotational spring is included in the structural model, as the idealised rigid connection is unable to properly capture the mechanical interaction between the constituent plates. Both bending and shear deformation in the cross-sectional constituent members is taken into account. The model is shown to have high precision in terms of predicting the transverse shear stiffness when compared with numerical analyses. Furthermore, high precision is also shown when it comes to predicting normal stresses in the constituent members of the panel with respect to shear action. In a case study included in this paper, the impact of having two weld lines compared with a single weld was studied, together with the effect of the distance between the welds. The results show a large impact with respect to shear stiffness and stresses in the constituent plates. This paper focuses on laser-welded corrugated core steel sandwich panels, but the presented model can also be used for analyses of general continuous core shapes and other isotropic materials.