ABSTRACT
Sandwich panels are generally used as building envelopes in industrial and commercial buildings. They consist of two metallic face sheets and a core that provides the heat-insulating function of these components. The core material most commonly used is polyurethane (PUR) rigid foam. Due to the factory production of the sandwich panels, they can be quickly installed on the building and meet high building physics requirements. For those reasons, they are ideally suited for reuse. In addition, there is currently little to no possibility of recycling rigid polyurethane foam. Furthermore, recycling the steel is also energy-intensive and requires complex separation of the materials. The reuse of sandwich panels is therefore not only possible but also necessary from an ecological point of view. In this context, it is important to be able to assess the load-bearing behaviour of the panels after the first life-cycle in order to ensure a safe design. Generally, the material properties of the composite panels are determined by tests according to EN 14509, 2013. The modulus of elasticity and the shear modulus as well as the tensile, compression and shear strengths are determined in small specimen tests. The wrinkling stress of the panels is determined by component tests. Due to the size and number of test specimens, the effort to determine the wrinkling stress by tests is generally very high. To ensure that the reuse of sandwich panels remains attractive, the effort required to determine the material properties must be as low as possible. Avoiding the tests to determine the wrinkling stress could make an important contribution. This paper presents investigations to determine the wrinkling stress based on small-scale tests and numerical simulations, which represent an important step towards the reuse of sandwich panels.
