Measurement of Transverse Permeability of Fabric Preforms Using Ultrasound Monitoring Technique in LCM Processes

Abstract

Processes of the Liquid Composite Molding (LCM) are widely used in composites produced by impregnation of a dry preform with liquid resin. The resin flow through the preform is usually described by Darcy’s law and the permeability tensor must be obtained for filling process analysis and characterizing the ability of a porous material to be impregnated by a resin fluid. In generally, resin flow in the thickness direction can be neglected for thin parts, but the resin flow in the transverse direction is important for thicker parts. In this study, the transverse permeability measurement device using ultrasound method was developed, the transverse flowfront could be calculated, and global effective permeability and transverse were studied.

RTM molding simulation for unidirectional fiber reinforced composite components considering local fiber orientation and fiber volume fraction

“…Magagnato, Henning RTM simulation for UD reinforced composites The influence of the through-plane permeability, K3, can usually be neglected because of relative small thicknesses of composite parts compared to other dimensions [20]. For unidirectional fabrics, K3 should be in the same order of magnitude as K2.…”

Process-Oriented Determination of Preform Permeability and Matrix Viscosity during Mold Filling in Resin Transfer Molding

“…For the unidirectional fibers the direction with best permeability, K 1 , is parallel to the fibers and the worst permeability K 2 is normal to the fiber direction. The permeability in thickness direction, K 3 , can be neglected because of the small thickness of the composites parts [2]. Unfortunately, there is yet no normed procedure to determine the permeability experimentally [3,4], which results in a certain confusion at the calculation.…”

Experimental characterization to determine the influence of different binder systems on the preform permeability during RTM manufacturing

“…For the unidirectional fibers the direction with best permeability, K 1, is parallel to the fibers and the worst permeability K 2 is normal to the fiber direction. The permeability in thickness direction, K 3 , can be neglected, because of the small thickness of the composites parts [6]. Unfortunately, there is yet no standard norm to determine the permeability experimentally [7,8], which results in a certain confusion at the calculation.…”