Experimental and numerical forming of sandwich structures consisting of thermoplastic laminates and soft-elastic foam

Abstract

Sandwich structures have a pivotal role in the development of lightweight structures. In addition to their outstanding mechanical properties compared to monolithic materials, they offer high potential in integrating functions such as acoustic and thermal insulation. Depending on the requirements, the materials for the face sheets and the core can be varied. Typically, the core has high compressive and flexural stiffness, which makes it challenging to produce complex-shaped sandwich structures through a forming process without partially damaging the core. In this context, sandwich structures comprising a soft-elastic foam core and organic sheets as face sheets are of particular interest. The soft-elastic foam core allows for the integration of acoustic and thermal insulating properties while enabling low-damage forming. To this end, the influence of foam thickness and contour as well as the integration of vacuum-assistance in the forming process on the dimensional accuracy are experimentally analysed. Additionally, a model for simulating the forming process is developed and validated based on the dimensional accuracy.