TY - BOOK

T1 - Development and implementation of sensing applications for fiber reinforced polymeric composites

AU - Konstantopoulos, Spyridon

N1 - no embargo

PY - 2016

Y1 - 2016

N2 - The needs for high performance lightweight structures and timely defect detection has resulted in the continuous improvement of the development, production and service stages of a fiber reinforced polymeric composite. The key tool that enables this improvement are sensors: Process Optimization, Non-Destructive Testing and Structural Health Monitoring are scientific areas addressing all stages of the lifetime of a structure and are based on appropriate usage of sensing technologies. In this thesis, the research frontier in the usage of sensors in these areas is identified and brought forward. A comprehensive review of the state-of-the art in the field was the starting point: All sensing technologies were analyzed with respect to their principles of operation, applicability to composites and limitations while past studies that exploited them were thoroughly examined. The benefit of using sensors in the development stage was investigated in the context of preform characterization which can lead to reliable simulations: Novel methods for the determination of the transverse and curvature permeabilities by ultrasound and electrical resistance measurements respectively were developed and applied for the characterization of a variety of preforms. Interesting results of these applications involved the identification of the influence of preform thickness and draping on permeability. In the production stage, sensor usage is expressed by process monitoring which has the potential of intelligent control of processes. The contribution in this topic was a novel method for cure monitoring based on live processing of temperature measurements through the spectrum of thermal analysis and kinetic theory. Interesting results were reached by calorimetric measurements of composite samples while an application with infrared thermography allowed non-invasive cure monitoring of large areas with a single system. Finally, a special topic of structural health monitoring was examined, aiming for applications in the service stage of the structure: A magnetic microwire sensor that when embedded in the part can produce measurements of the stress the part is subjected in. The work in this topic was about the characterization of the wire for the identification of the measurement principle and the development of an interrogation unit appropriate for stress detection. All of the above work was summarized and critically discussed in the final chapter of the thesis.

AB - The needs for high performance lightweight structures and timely defect detection has resulted in the continuous improvement of the development, production and service stages of a fiber reinforced polymeric composite. The key tool that enables this improvement are sensors: Process Optimization, Non-Destructive Testing and Structural Health Monitoring are scientific areas addressing all stages of the lifetime of a structure and are based on appropriate usage of sensing technologies. In this thesis, the research frontier in the usage of sensors in these areas is identified and brought forward. A comprehensive review of the state-of-the art in the field was the starting point: All sensing technologies were analyzed with respect to their principles of operation, applicability to composites and limitations while past studies that exploited them were thoroughly examined. The benefit of using sensors in the development stage was investigated in the context of preform characterization which can lead to reliable simulations: Novel methods for the determination of the transverse and curvature permeabilities by ultrasound and electrical resistance measurements respectively were developed and applied for the characterization of a variety of preforms. Interesting results of these applications involved the identification of the influence of preform thickness and draping on permeability. In the production stage, sensor usage is expressed by process monitoring which has the potential of intelligent control of processes. The contribution in this topic was a novel method for cure monitoring based on live processing of temperature measurements through the spectrum of thermal analysis and kinetic theory. Interesting results were reached by calorimetric measurements of composite samples while an application with infrared thermography allowed non-invasive cure monitoring of large areas with a single system. Finally, a special topic of structural health monitoring was examined, aiming for applications in the service stage of the structure: A magnetic microwire sensor that when embedded in the part can produce measurements of the stress the part is subjected in. The work in this topic was about the characterization of the wire for the identification of the measurement principle and the development of an interrogation unit appropriate for stress detection. All of the above work was summarized and critically discussed in the final chapter of the thesis.

M3 - Doctoral Thesis

ER -