Projects

TraClight - HyWet – Cost and resource efficient manufacturing of FRP-metal hybrid structures in Wet Compression Molding

The overall strategic goal of the project is to strengthen the transatlantic cooperation between German and North American companies in the field of lightweight construction. This includes the pooling of competencies, the joint advancement of current research topics and the development of new and effective cooperation mechanisms. The overall scientific objective of the project is the development of advanced technologies for hybrid Wet Compression molding, which enables an economical production of complex, FRP-metal hybrid structures in large quantities for automotive applications.

Currently, there are three main trends in automotive lightweight construction: (1) The use of high-strength metal alloys, (2) substituting metals by composites, and (3) the combination of hybrid materials. By using high-strength metal alloys, the wall thickness of structures can be reduced. However, once a critical minimum thickness is reached, designers can expect stability problems. Thus, the potential of high strength materials for lightweight construction is limited. The second approach: substituting conventional construction materials by high performance composites like carbon fiber reinforced plastics (CFRP) allows considerable weight savings but is restricted to small series vehicles due to relatively long cycle times and high material costs. A promising alternative are structural components realized in multi-material design.

In this context, the HyWet project investigates the cost efficient and robust manufacturing of FRP-metal hybrid structures consisting of sheet metal blanks made of steel or aluminum with a local FRP reinforcement. A promising approach to overcome the cost issues is the hybrid Wet Compression Molding technology where a textile semi-finished product is wetted by a resin and directly formed into a sheet metal structure. In this case, the adhesion of the sheet metal and composite is realized by co-molding whereby the chosen resin takes the role of an adhesive. After the forming and co-molding process, the tool is kept closed for further curing of the FRP reinforcement.

Tailored placed fabric
© Fraunhofer ICT
Tailored placed fabric
Composite manufactured in Wet Compression Molding process
© Fraunhofer ICT
Composite manufactured in Wet Compression Molding process