3D real time and in situ observation of the fibre orientation during the plane strain flow of concentrated fibre suspensions

Short-fibre reinforced polymer composites are increasingly used as structural or functional components in many engineering fields. To obtain high-performance composite materials, the matrices with high fibre contents (>20–50 wt%). Hence, during their forming, behave concentrated suspensions that exhibit a non-Newtonian rheology. In addition, end-use properties depend on orientation which drastically evolves forming operations. Within this context, it is crucial to analyse induced microstructure changes flowing suspensions. For purpose, 3D situ compression experiments were performed model imaged using fast X-ray synchrotron microtomography. At scale, large fluctuations translation and rotation of fibres observed compression. These shown be same order magnitude than mean They can attributed long-range hydrodynamic interactions between neighbouring well short-range by numerous fibre-fibre contacts practically follow trends predicted tube model. Surprisingly, spite chaotic kinematics fibres, macroscopic deformation suspension was homogeneous flow-induced evolution found described averaged Jeffery's equation (related second tensor).