Identifikation von Werkstoffmodellparametern zur Berechnung von Klebverbindungen unter Crashbelastung

Adhesive joints of the car body have to conserve their integrity under crash loading and thus allow the whole structure to consume a large amount of dissipation energy. To meet the respective requirements the glue must exhibit high strength as well as high fracture strain. The specific properties of adhesives require complex material models that must take into account plastic dilatancy under tension load and almost plastic incompressible behaviour under pressure, strain rate sensitivity of strength and fracture strain; furthermore plastic flow is nonassociative. Therefore, material models for adhesives require a set of parameters that have to be determined by experiments. Specimens of pure adhesives allow the material characterization under well defined boundary conditions but it is not fully clear whether they represent the properties of the glue in adhesive joints. Therefore tests have also been performed for bonded specimens and a comparison between the flow and failure behaviour of both types of specimens has been made and conclusions for the parameter identification were drawn.