This report addresses a master thesis carried out by a mechanical engineering student at Lulea University of Technology. The thesis was conducted at Gestamp HardTech in the spring of 2019. The goal of the thesis was to design a Door Ring with carbon fiber reinforced polymer patches which was supposed to be lighter and have equally as good crash performance as the existing all-steel solution.

In order to fulfil the goal of the thesis the generated designs were tested in full car crash simulations. Full car crash simulations of the old designs were also conducted to get references to compare the results to. The full car crash simulations were conducted on the G-LAB 10 version 0.8 and the simulations were set up to mimic the Side Impact MDB, Small Frontal OVerlap and Roof Strength test of the IIHS standard. The final design that was generated in this thesis was the outcome of an iterative design process that were developed to optimize both performance and weight of the Door Ring.

A final design suggestion is made in this report. The final design matches the performance of the all-steel solution and is 1.55 kg lighter. A weight decrease of 1.55 kg is equal to a weight reduction of 10.6 %.

In the end of the report the results are discussed, conclusions are made and future work is suggested.