Investigation and Experimental Validation of a Novel Shelter with a Paraboloid-Like Steel Roof Structure

The decades-long development of curvilinear steel bar forms has relied on both physical and analytical modelling. This study integrates these complementary approaches to optimise the geometry and topology of a paraboloid-like steel bar structure, with the aim of enhancing structural performance and material efficiency. The developed method introduces a novel Discrete Catenary Model (DCM), generated through dynamic relaxation, to define the geometry of a steel bar roof suitable for flat quadrilateral (PQ) parallelogram panels. The DCMs were arranged in parallel at equal spacing, forming a bar grid supported by four corner columns. Static analyses were performed for various cladding materials-glass, polycarbonate, and metal sheets-to compare structural material demands, with serviceability limit states for nodal displacements and member deformations serving as key criteria. The proportions of structural material consumption for structures with glass, polycarbonate, and metal panels were 1.00:0.68:0.61. For the glass-clad variant, a physical prototype of a recreational shelter was developed and subjected to laboratory testing under near-real conditions. The test results confirmed the analytical predictions regarding the structural response under loading; the differences in nodal displacements were in the order of tenths of a millimetre. The findings indicate that the application of a parametric DCM makes it possible to obtain the intended and efficient geometry already at the preliminary design stage. Therefore, the generation of a DCM can serve as a practical tool for shaping efficient curvilinear steel bar structures with PQ panels. The proposed original method can be further developed through alternative DCM forms to design efficient steel bar roof systems.