This master thesis is written as the final assignment in Industrial Design Engineering at Luleå University of Technology (LTU), spring 2018, on behalf of Gestamp HardTech in Luleå. The goal of the project was to design three steel-CFRP components (A-pillar, Roof Arch Front and Roof Arch Mid) in a way that the total weight of the component is reduced while increasing or maintaining the current performance. 

To get a deeper understanding on the current situation and to gather the knowledge needed to perform the given task, theory regarding materials, adhesives, CAE, CAD and software were gathered. In order to generate ideas for the three components, a workshop and different brainstorming techniques have been utilized together with an idea selection method, to select the ideas that are suitable for further development. The ideas selected were then simulated and optimized by creating design variations to variables such as, the thickness, shape and fiber orientation of the different layers to achieve a desired behavior.

When the concept development of the three concepts was completed and a desirable performance had been reached, three prototypes of the concept developed for the A-Pillar were manufactured at Swerea Sicomp in Piteå. The three prototypes were manufactured using a hand-layup with pre-impregnated carbon fiber fabric. Two of the three concepts were then tested in a drop tower test rig at Gestamp HardTech in order to compare the performance of the new CFRP-patch with the original steel design.

The testing performed in the drop rig showed that the performance of the prototype using carbon fiber had a comparable performance with that of the steel patch. The reference and the prototype showed a similar behavior in the load-intrusion graphs as well as a close to identical energy absorption at an intrusion of 200 mm despite the slight difference in the deformation of the A-Pillar in comparison to the reference. The concept development resulted in a significant weight reduction of the three components while the performance could be preserved.

For further work, a more realistic submodel without dummy, or modified components is recommended in order to achieve a reliable test setup, where accurate conclusions and decisions can be made. Furthermore, a more detailed analysis using other testing methods on the three components have to be conducted in order to make further improvements.