Non-Destructive Impact Damage Detection on Carbon Fiber Reinforced Plastics IDD-Metro within BRAGECRIM

• Applicant: Professor Dr.-Ing. Robert Heinrich Schmitt
• Subject Area: Production Systems, Operations Management, Quality Management and Factory Planning
• Term: from 2014 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 262376261

The reduction of weight of products using lightweight carbon-fibre-reinforced plastics (CFRP) is an enabler for the industry to save energy and face the international climate objectives and increasing energy costs. CFRP are characterized by a high specific stiffness and strength, which make them ideal for lightweight applications in e.g. aviation industry, wind turbines, automotive industry and even consumer goods industry. In fact, new electric vehicles have been introduced recently considering a significant amount of CFRP in the support structure, thus reducing weight and enhancing driving dynamics. The demand of CFRP is expected to grow in the coming years, since the use of CFRP expands from small batch production to mass production. The economic feasibility of CFRP products must be assured throughout the whole product life cycle. Therefore, the long term operational reliability and economic repair processes must be assured. The established concepts from aircraft and aerospace industry base upon manual processes and in general demand a replacement of damaged parts. A mass production of CFRP products requires economically feasible and efficient repair processes. Therefore, non-destructive, reliable, efficient and automated measurement technology is required to fit the material, component and repair work shop specific requirements. The development of portable and non-destructive testing methods, which reliably and holistically detect defects, is inevitable. Thermography is well suited for the non-destructive detection of defects in CFRP. Thermography systems are portable, cover large areas and are time efficient. The thermography is based on 2D images. These images contain an overlay of the different layers of the sample (depth information). But, the absolute position and size of the defect on the component and its depth information are not directly accessible. The objective of this project is to design, develop and setup a system to reliably detect impact damages with their respective properties (size, shape, position and depth) in CFRP components that enables a reliable repair process in the workshop environment. This goal will be achieved by enhancing the thermography to detect those 3D properties of defects in carbon fiber-reinforced plastics. CFRP samples with different impact defects will be studied with thermography, shearography and CT. From the CT results, a defect classification will be drawn, considering properties like the depth and geometry of the defects and the severity of the damage. Fusing the results from aforementioned measuring techniques, an evaluation model will be created. The model will be integrated into a demonstrator and validated. The additional benefits from this project are measurement strategies for thermography and CT to better quantify the CFRP damages. The results will improve the quality assurance of CFRP and will enable reliable repair processes. The model can be extended to other materials and defects.

• DFG Programme: Research Grants
• International Connection: Brazil
• Cooperation Partners: Professor Dr. Armando Albertazzi Goncalves; Professor Dr. Crhistian Raffaelo Baldo