Suitability analysis of a polymer–metal hybrid technology based on high-strength steels and direct polymer-to-metal adhesion for use in load-bearing automotive body-in-white applications

A comprehensive set of computational engineering analyses is carried out in order to assess the suitability of a “direct adhesion” polymer–metal hybrid (PMH) technology for use in load-bearing automotive body-in-white (BIW) components. Within the direct adhesion PMH technology, load transfer between stamped sheet-metal and injection-molded rib-like plastic subcomponents is accomplished through a variety of nanometer-to-micron scale chemical and mechanical phenomena which enable direct adhesion between the two materials. The resultant adhesion strength in a 5–10 MPa range has been assessed. In the present work it has been investigated if such level of adhesion strength is sufficient to restore the component's stiffness in the cases when stiffness has been compromised by substituting a twin-shell large-thickness drawing-quality-steel design of a prototypical BIW component with a single-shell lower-thickness high-strength-steel and polymer-hybridized design of the same component. The results obtained suggest that meeting the bending stiffness requirements is the most challenging task and if such requirements do not control the overall component design, weight savings in a 2.0–2.5% range can be obtained.