Eric Man Pradhan, M.Sc.

The sandwich panels used in the construction industry are fabricated from two thin metallic face sheets, which are connected to each other in a shear-resistant manner typically by a polyurethane (PU) or mineral wool core layer. These sandwich panels have become a cost-effective solution for roof and wall components, particularly in industrial construction. In addition to their efficient lightweight construction, they are distinguished by their effective insulating and sealing properties, short installation time, and low manufacturing costs.

A newly developed application for new buildings and renovations is the sandwich panel with an supplementary curtain wall. Here, additional, architecturally customisable facade units are attached eccentrically to the outside of a sandwich wall panel via rails. As the primary load-bearing façade structure, the sandwich panels are thus subjected to a torsional moment due to the weight of the curtain wall. The similiar structural behaviour is to be expected in the case of sandwich wall panels equipped with photovoltaic panels or a green façade.

The calculation of eccentrically loaded sandwich panels has, thus far, been predominantly based on St. Venant's torsion theory of bars with thin-walled cross-sections. However, full-scale tests at the IFSW demonstrated that this simplification is not justified, as the torsional stiffness can be significantly overestimated, by a factor of 1.5 to 10. Furthermore, the warping and normal stresses in the longitudinal direction of the component induced by torsional loading, as determined in initial numerical investigations, also support this conclusion.

The objective is to develop a novel approach that incorporates the warping torsion theory to assess the load-bearing behaviour and load-bearing capacity of eccentrically loaded sandwich panels with sufficient accuracy. For this purpose, further experimental and numerical studies are required to evaluate the planar structural behaviour of eccentrically loaded sandwich panels.

Further information on the current state of research can be found in the following publication

Pradhan, E. M.; Lange, J.:Warping Torsion in Sandwich Panels: Analyzing the Structural Behavior through Experimental and Numerical Studies. Materials 2024, 17, 460.