Model Calibration and Data Set Determination Considering the Local Micro-Structure for Short Fiber Reinforced Polymers

To ensure the usability of parts made of fiber-reinforced polymers, a lifetime assessment has to be made in an early stage of the development process. To describe the whole life cycle of these parts, continuous simulation chains can be used. From production to the end of the service life, all influences are mapped virtually. The later material strength is already given after the manufacturing process due to the process dependent fiber alignment. To be able to describe this fiber orientation within the lifetime assessment, this paper presents an approach for model calibration and data set determination to consider the local micro-structure. Therefore, quasi-static and cyclic tests were performed on specimens with longitudinal and transversal fiber orientation. A supplementary failure analysis provides additional information about the local micro-structure. The local fiber orientation is determined with mu CT (micro computer tomography)-measurements, correlated to the extraction positions of the specimen, and implemented in a dataset. With an attached lifetime calculation on a demonstrator, a major influence of the local micro-structure on the calculation results can be shown. Therefore, it is indispensable to consider the local fiber orientation in the data set determination of short fiber reinforced polymers.

Automated summary

This study highlights the importance of considering the local micro-structure in the data set determination for short fiber reinforced polymers using model calibration and data set determination methods. The research involved quasi-static and cyclic tests on specimens with different fiber orientations, as well as micro CT measurements to determine local fiber orientation. The results showed a significant influence of local micro-structure on the calculation results, emphasizing the necessity of incorporating this factor in lifetime assessment of parts made of fiber-reinforced polymers.