Back to overview

Lecture

Computed Tomography Examination of Hybrid Components after Dynamic 3-Point Bending Test

Thursday (09.11.2017)
11:35 - 11:55
Part of:


Based on legal requirements, the emission of carbon dioxide of motorized vehicles must be reduced. Beside increasing the efficiency of combustion engines and using alternatives such as electric motors and hybrid drive technologies, the current goal can be achieved by weight reduction using fiber-reinforced plastics, which reduce the car body weight significantly accompanied by an increase in the component costs. Hybrid materials, such as the combination of steel or aluminum and carbon-fiber-reinforced plastic (CFRP), present an adequate solution for lightweight construction and provide a cost-effective alternative combined with sufficient high strength and stiffness.

Goal of this work is to examine hybrid components made of CFRP and aluminum before and after crash tests by using computed tomography (CT). Crash loading is reproduced by a dynamic 3-point bending test. The components are manufactured using a modified RTM-process. The aluminum profile and the unidirectional carbon fiber preforms are first inserted into the cavity of the RTM tool. The injected epoxy resin serves as a matrix for the CFRP and as an adhesive to the aluminum.

The bonding between CFRP and aluminum plays a crucial role in transmitting forces into the CFRP and particularly into the carbon fibers. In this work, a variety of surface treatments is examined in order to observe the influence on the energy absorption under crash loadings. CT scans throughout the manufacturing process and after the test lead to the identification of the particular damage mechanisms.

First CT scans show two problems in the manufacturing process. The top layer of the preforms is damaged and the parallelism of the fibers is affected by the manual cutting process of the preforms. This confirms, that the mechanical stress during this process must be kept as low as possible. Observing the produced hybrid components, it’s shown that the fibers are pulled up into the exit vent of the molding tool, where a vacuum is applied during the manufacturing process. All of the unidirectional carbon fiber layers are affected by this problem, which leads to a lower strength of the hybrid component, since the full potential of fibers can only be exploited if no undulation occurs.

 

Speaker:
Philipp Kutz
Bielefeld University of Applied Sciences
Additional Authors:
  • Zheng Wang
    University of Pderborn
  • Dr. Manel Ellouz
    University of applied sciences Bielefeld
  • Prof. Dr. Thomas Kordisch
    University of applied sciences Bielefeld
  • Prof. Dr. Thomas Troester
    University of Pderborn

Dateien

Category Short file description File description File Size
Short Paper Short Paper LighMat 2017 Philipp Kutz This is the short paper for the submission "Computed Tomography Examination of Hybrid Components after Dynamic 3-Point Bending Test" 350 KB Download