Project Details
Projekt
Effects, Detection and Prediction of Defects in Hybrid Composite Parts for Metal/CFRP-Lightweight Structural Structures Suitable to Large-Volume-Production
Applicants
Professor Dr.-Ing. Hans-Georg Herrmann; Professorin Dr.-Ing. Gisela Lanza; Professor Dr.-Ing. Markus Stommel
Subject Area
Primary Shaping and Reshaping Technology, Additive Manufacturing
Plastics Engineering
Plastics Engineering
Term
from 2014 to 2021
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 255886929
The research on innovative joining elements offers the potential to increase the field of applications in the use of carbon fibre reinforced plastics (CFRP). In order to reach this goal it is necessary to evaluate their functional capability under scientific aspects. These aspects concern the design and dimensioning but also the production of parts. In the Priority Programme 1712 it could already be shown that quality critical defects need to be detected during the production process itself because they significantly contribute to a decreased functionality of the joint connection between CFRP and inserted components (Inserts). This finding was made during a so called Effects of Defects analysis, where both part and material specific defects were purposely inserted into two-dimensional and curved joints. Mechanical testing methods have shown the influences of individual defects on load bearing capacity and other part properties leading to the identification of critical defect types. By applying methods of non-destructive testing simultaneously to the mechanical testing typical failure behaviour could be directly linked to the defect types, leading to the necessity of their detection in the Resin Transfer Moulding process chain by in-line measurement systems. The goal of the project is based on the results of the described preliminary project. Therefore it is necessary to create a basic method for the development of three-dimensional hybrid joints and to determine the dimensions of potential critical defects that are weakening the bond. The findings are used in a three-staged control loop approach that is associated with the design, non-destructive testing as well as the production of hybrid parts. In the field of design, innovative methods of part construction are developed and applied in order to influence the damage propagation inside the joint due to quality critical defects. By manufacturing parts with purposely inserted defects of varying dimensions and locations the application of innovative methods such as the inductive thermography allows the analysis of different damage cases. In addition to the results of the preliminary project phase, this approach not only allows the identification of critical defects but also the determination of critical defect sizes and their positions that need to be detected in production. In order to do so, methods of process integration are investigated for the integration of thermography and ultrasonic testing in the production process for the quality control of manufactured parts. For the simultaneous application of different measurement principles a data fusion approach need to be investigated in order to enable a combined analysis of thermal, acoustic as well as optical data resulting from the preliminary project. Furthermore the findings of the damage analysis are returned to the field of design in order to increase the insensitivity of the hybrid joint towards critical defects and their characteristics.
DFG Programme
Priority Programmes
