Juliane Blarr Juliane Blarr

Research Area Characterization – C2:Microstructural characterization

Microstructural (in-situ) characterization of CoDiCoFRTP under near-service conditions based on volumetric CT images

Advisors: Elsner (IAM-WK), Inal (UWaterloo)

Based on experience gained in generations one and two, the research focus, as well as the methods used, will be transferred to the investigation of CoDiCoFRTP based on long fiber reinforced thermoplastics (LFT), featuring pronounced fiber curvature and broad fiber length distributions (possible validation by thermogravimetric analysis (TGA) in cooperation with C3). Due to the use of carbon fiber reinforced thermoplastics and the associated contrast minimization, previously developed methods and algorithms may need to be adapted to the new material system.

Additionally, investigating the material behavior under elevated temperatures and humidity influence to explore the impact on the damage behavior is of utmost interest in contrast to the thermoset-based material systems investigated in generation one and two. Therefore, the in-situ stage will be expanded to regulate temperature and humidity in order to be able to implement tensile and possibly bending tests at different climatic conditions therein. Machine learning methods can be used for automated crack detection. The knowledge obtained from these experiments could, in turn, be incorporated into a holistic thermo-viscoelastic material model and therefore be performed in collaboration with S1, S2, S3, and S4.

In addition, samples shall be exposed to corrosive fluids and subsequently tested in-situ using X-ray computed tomography to observe the impact of a corrosive environment on the constituents and the interface. The effects of hydrothermal aging on material properties can also be captured on a multi-scale basis in collaboration with C3.

Figure 1: Computed tomography image of a carbon fiber reinforced polyamide microstructure

Figure 2: µCT-in-situ device for tensile tests