Resin flow front monitoring in RTM

1998 ◽  
Vol 42 (2) ◽  
pp. 30-32
Keyword(s):  
Resin Flow ◽  
Flow Front

Determination of the Permeability Tensor of Fibrous Reinforcements for VARTM

1999 ◽  
Author(s):  
Pavel B. Nedanov ◽  
Suresh G. Advani ◽  
Shawn W. Walsh ◽  
William O. Ballata
Keyword(s):  
Constant Pressure ◽  
Permeability Tensor ◽  
Three Dimensions ◽  
Resin Flow ◽  
Flow Front ◽  
Resin Impregnation ◽  
Permeable Media ◽  
Front Position ◽  
Transverse Permeability

Abstract VARTM and SCRIMP composite manufacturing processes use a highly permeable media to distribute the resin through the thickness of the composite. Hence, manufacturing simulations of resin flow in such processes requires reliable data for in-plane as well as transverse permeability. The goal of this study is to propose a method for simultaneous determination of the principal values of 3D-permeability tensor of fibrous reinforcements. The permeability components are calculated from experimental data, consisting of flow front position with time during resin impregnation in three dimensions from a radial source under constant pressure using the SMARTweave [Walsh (1993), Fink et al.(1995)] sensor system. Experimental results are compared with numerical simulation.

A Distribution Medium Considered Resin Flow Simulation Model for Vacuum Infusion Molding Process

2013 ◽  
Vol 753-755 ◽  
pp. 221-224
Author(s):  
Rui Yang ◽  
Long Tao Li ◽  
Yan Xin Zhao
Keyword(s):  
Simulation Model ◽  
Layer Thickness ◽  
Flow Simulation ◽  
Parabolic Type ◽  
Resin Matrix ◽  
Resin Flow ◽  
Flow Front ◽  
Molding Process ◽  
Fiber Layer ◽  
Front Profile

Based on the flow characteristics of resin in fiber perform, a simulation model considering distribution medium was developed, and impregnation of fiberglass reinforced resin matrix composites was numerically simulated. The fiberglass layer thickness on VIMP microscopic impregnation was analyzed in simulation. The results show that increasing fiberglass layer thickness can reduce the flow velocity of the resin and the resin flow front profile approximates a straight line type, so the fluctuation is small, and the final product has few dry spots; reducing the glass fiber layer thickness can improve wetting speed but resin flow front profile approximates a parabolic type, so the fluctuation is large, and the final product has more dry spots, the resin flow front profile can provide guidance for prediction and optimization of the infusion process.

Embedding Intelligence for RTM Process Monitoring and Control

2008 ◽  
Vol 56 ◽  
pp. 530-533
Author(s):  
R. Caponetto ◽  
Gianluca Cicala ◽  
G. Dongola ◽  
F. Filippino ◽  
G. Recca
Keyword(s):  
Linear Trend ◽  
Characteristic Curve ◽  
Resin Flow ◽  
Monitoring And Control ◽  
Flow Front ◽  
Rtm Process ◽  
Capacitance Variation ◽  
Embedded Capacitor ◽  
Process Monitoring And Control ◽  
And Control

A technique to control the resin flow front in closed and open mould is described. The technique consists in embedding linear capacitive sensors to provide the position of the moving flow front. The embedded capacitor is made with two parallel wires while the resin, between the wires, acts as a moving dielectric which changes the capacitance values. Therefore the position of the resin is obtained from the measured capacitance variation. In order to validate the proposed methodology the sensor has been characterized and the obtained characteristic curve showed a quasi-linear trend. The shape of the resin front could be modified, if necessary, acting locally with controlled injectors.

Numerical modeling and experimental validation of nonisothermal resin infusion and cure processes in large composites

2017 ◽  
Vol 36 (10) ◽  
pp. 780-794 ◽  
Author(s):  
Liangkai Ma ◽  
Siddharth R Athreya ◽  
Rujul Mehta ◽  
Dev Barpanda ◽  
Asjad Shafi
Keyword(s):  
Material Properties ◽  
Experimental Validation ◽  
Flow Direction ◽  
Resin Flow ◽  
Flow Front ◽  
Fiber Preform ◽  
Resin Infusion ◽  
Transfer Molding ◽  
Model Predictions ◽  
Front Profile

This paper presents an experimentally validated model to simulate the nonisothermal resin infusion and cure processes in a relatively large and thick composite laminate fabricated using vacuum-assisted resin transfer molding. Compaction effects were accounted for by using a step-wise scheme wherein the panel was divided into three discrete zones along the flow direction, with each zone being assigned different porosities and other material properties. The experimentally observed dynamic evolution of the resin flow front profile due to permeability difference between the high-permeable infusion medium and the glass-fiber preform as well as the heat transfer in the preheated system was captured accurately. Both model predictions and experimental measurements indicate subtle variation in the spatiotemporal distributions of temperature and degrees of resin cure from the infusion stage can result in large differences in the resin cure profile across the laminate, which may cause undesirable residual stresses in large composites.

A Study on Resin Flow through a Multi-layered Preform in Resin Transfer Molding

2002 ◽  
Vol 10 (7) ◽  
pp. 493-510 ◽  
Author(s):  
D. G. Seong ◽  
K Chung ◽  
T. J. Kang ◽  
J. R. Youn
Keyword(s):  
Resin Transfer Molding ◽  
Mold Filling ◽  
Transverse Flow ◽  
Woven Fabrics ◽  
Weighted Averaging ◽  
Resin Flow ◽  
Flow Front ◽  
Transfer Molding ◽  
Filling Time ◽  
Flow Through

In resin transfer molding, mold filling is governed by the flow of resin through a preform which is considered as an anisotropic porous media. The resin flow is usually described by Darcy's law and the permeability tensor must be obtained for filling analysis. When the preform is composed of more than two layers with different in-plane permeability, effective average permeability should be determined for the flow analysis in the mold. The most frequently used averaging scheme is the weighted averaging scheme, but it does not account for the transverse flow between adjacent layers. A new averaging scheme is suggested to predict the effective average permeability of the multi-layered preform, which accounts for the transverse flow effect. When the flow in the mold is unsaturated, the effective average permeability is predicted by using the predicted mold filling time and transverse permeability. The new scheme is verified by measuring the effective permeability of the multi-layered preforms which consist of glass fiber random mats, carbon fiber woven fabrics, aramid fiber woven fabrics. Fluid flow through the preform composed of more than two layers with different in-plane permeability shows different flow fronts between layers. The difference in the flow front advancement is observed with a digital camcorder. The predicted flow front is compared with the experimental results and shows a good agreement. It is expected that the effective average permeability can be used for modeling the resin flow through the multi-layered preform.

scholarly journals Influence of the micro-structure on saturated transverse flow in fibre arrays

2018 ◽  
Vol 52 (18) ◽  
pp. 2463-2475 ◽  
Author(s):  
Frank Gommer ◽  
Andreas Endruweit ◽  
Andrew C Long
Keyword(s):  
Transverse Flow ◽  
Fibre Volume ◽  
Resin Flow ◽  
Flow Front ◽  
Micro Structure ◽  
Fibre Bundles ◽  
Volume Fractions ◽  
Flow Length ◽  
High Fibre ◽  
Micro Structures

This study analyses the influence of the random filament arrangement in fibre bundles on the resin flow behaviour. Transverse steady-state resin flow that occurs behind a liquid resin flow front was simulated numerically through statistically equivalent micro-structures at high-fibre volume fractions, Vf > 0.6, as observed in fibre bundles. The need of applying a minimum gap distance between neighbouring filaments was overcome by automated local mesh refinement. The derived permeability values showed significant scatter. Convergence of these values was determined at a ratio of flow length to filament radius greater than 20 for all three analysed fibre volume fractions. Mean permeabilities were between 6 and 10 times lower than those predicted for a hexagonal fibre array. A statistical model is proposed, which is able to predict the scatter of observed permeabilities based on simple micro-structural descriptors.

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