Four point bend test on lightweight panels

The Dresden-based company VENTUM-S is a manufacturer of modular stage constructions. For the series production of their newly developed lightweight panel, the required load-bearing capacity of 750 kg/m² was to be proven in experimental tests by the Otto Mohr Laboratory. This new development features maximum weight reduction with full functionality compared to other constructions. The lightweight panel consists of a 1.2 mm thick foam core and a 6 mm thick plywood layer on both sides.

To demonstrate the performance of this newly developed product, a load test was performed on a lightweight panel in a four-point bending test. This panel was 2.00 m long and 1.00 m wide and was supported on a load-bearing system (Praktikabel) used for such platforms or stage structures. Load distribution by means of steel girders was chosen to transfer the loads to the lightweight slab. A hydraulic cylinder was used to apply the load to the panel in stages with intermediate unloading until the required load capacity of 750 kg/m² was reached. The deformations were measured with inductive displacement transducers at selected points. The lightweight panel withstood the required load without any problems. From the data of the deformation measurement, it was further evident that the material behavior of the lightweight board can be classified as elastic.

In addition, platforms that are walked on by individual persons must withstand a vertical load of 1.5 kN/m² or an individual load of 1.5 kN. Since the latter is the significantly less favorable load, the slab was also subjected to a single load in the bending test. The load of 1.5 kN was also applied to the plate in stages using a hydraulic cylinder with intermediate unloading. The lightweight panel also withstood this load case without any significant permanent deformation. Following successful verification of the load capacity, the new lightweight panel is now being produced in series.