Numerical Prediction of Permeability Tensor for Three Dimensional Circular Braided Preform by considering Intra-tow Flow

2005 ◽  
Vol 13 (4) ◽  
pp. 323-334 ◽  
Author(s):  
Y.S. Song ◽  
K. Chung ◽  
T.J. Kang ◽  
J.R. Youn
Keyword(s):  
Control Volume ◽  
Three Dimensional ◽  
Unit Cell ◽  
Permeability Tensor ◽  
Resin Flow ◽  
Resin Transfer Moulding ◽  
Moulding Process ◽  
Flow Through ◽  
Transfer Moulding ◽  
Control Volume Finite Element

Resin transfer moulding is characterized by the permeability tensor, which is a measure of the resistance to resin flow through the preform. Complete prediction of the second order permeability tensor for three dimensional circular braided preforms is critical to an understanding of the resin transfer moulding process. The permeability can be predicted by considering resin flow through the multi-axial fibre structure. In this study, the permeability tensor for a 3-D circular braided preform was calculated by solving a boundary problem of a periodic unit cell. The flow field through the unit cell was obtained by using a 3-D control volume finite element method (CVFEM) and Darcy's law was utilized to obtain the permeability tensor. The flow analyses were carried out for two cases, one in which the fibre tow was regarded as a permeable porous medium, and one in which it was regarded as an impermeable solid. It was found that the flow within the intra-tow region of the braided preform was negligible if the inter-tow porosity was relatively high, but flow through the tow, especially flow in the thickness direction must be considered when the porosity is low. The permeability of the braided preform was measured by a radial flow experiment and compared with the predicted permeability.

Simulation of air bubble’s creation, compression, and transport phenomena in resin transfer moulding

2017 ◽  
Vol 51 (29) ◽  
pp. 4115-4127 ◽  
Author(s):  
Bouchra Aaboud ◽  
Abdelghani Saouab ◽  
Yasir Nawab
Keyword(s):  
Control Volume ◽  
Air Bubbles ◽  
Resin Transfer Moulding ◽  
Fibrous Media ◽  
Composite Part ◽  
Simulation Code ◽  
Moulding Process ◽  
Transfer Moulding ◽  
Control Volume Finite Element

The presence of air bubbles impacts the quality of the produced composite part, by reducing its mechanical properties, and also it might degrade its surface finish. The modelling of air bubbles entrapment requires the consideration of three phenomena: air bubble’s creation, compression and transport. Very few studies have been conducted on this latter phenomenon. The model developed in this work is proposed for a unidirectional reinforcement. It is integrated into a simulation code of resin transfer moulding process, via the control volume finite element method. That model takes into account the dual scale pores in fibrous media, and simulates the three said phenomena highlighting the migration phenomenon and the coexistence of micro and macro air bubbles. As a result, the spatial distribution of created, compressed and transported air bubbles as well as its macro and micro remaining quantities, in the end of the injection are estimated.

Prediction of Permeability Tensor for Plain Woven Fabric by Using Control Volume Finite Element Method

2003 ◽  
Vol 11 (6) ◽  
pp. 465-476 ◽  
Author(s):  
Y. S. Song ◽  
K. Chung ◽  
T. J. Kang ◽  
J. R. Youn
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Control Volume ◽  
Three Dimensional ◽  
Woven Fabrics ◽  
Permeability Tensor ◽  
Woven Fabric ◽  
Stacking Order ◽  
Control Volume Finite Element ◽  
Element Method

The complete prediction of the second order permeability tensor for a three dimensional multi-axial preform is critical if we are to model and design the manufacturing process for composites by considering resin flow through a multi-axial fiber structure. In this study, the in-plane and transverse permeabilities for a woven fabric were predicted numerically by the coupled flow model, which combines microscopic and macroscopic flows. The microscopic and macroscopic flows were calculated by using 3-D CVFEM(control volume finite element method) for micro and macro unit cells. To avoid a checkerboard pressure field and improve the efficiency of numerical computation, a new interpolation function for velocity is proposed on the basis of analytical solutions. The permeability of a plain woven fabric was measured by means of an unidirectional flow experiment and compared with the permeability calculated numerically. Reverse and simple stacking of plain woven fabrics were taken into account and the relationship between the permeability and the structures of the preform such as the fiber volume fraction and stacking order is identified. Unlike other studies, the current study was based on a more realistic three dimensional unit cell. It was observed that in-plane flow is more dominant than transverse flow within the woven perform, and the effect of the stacking order of a multi-layered preform was negligible.

scholarly journals A Study on the Measurement Technique of Resin Flow and Cure during the Vacuum Assisted Resin Transfer Moulding Process using the Long Period Fibre Bragg Grating Sensor

2004 ◽  
Vol 13 (5) ◽  
pp. 096369350401300 ◽  
Author(s):  
Youngki Yoon ◽  
Seunghwan Chung ◽  
Woo Il Lee ◽  
Byoungho Lee
Keyword(s):  
Bragg Grating ◽  
Fibre Bragg Grating ◽  
Resin Flow ◽  
Resin Transfer Moulding ◽  
Moulding Process ◽  
Long Period ◽  
Curing Reaction ◽  
Glass Mat ◽  
Transfer Moulding ◽  
Vartm Process

Long Period Gratings (LPGs) are currently being used in various fibre-optic sensor implementations. In this study, Long Period Fibre Bragg Grating was applied to monitor the resin flow and the curing process in the Vacuum Assisted Resin Transfer Moulding (VARTM) process. The principle of measurement is explained. In order to demonstrate the effectiveness of the method, gratings are inserted into the glass mat to monitor the resin flow during VARTM process. Signal from the sensor is processed by an optical spectrum analyzer (OSA). The curing reaction is also monitored using the same method. From the results, it is shown that the proposed LPGs sensor is effective in monitoring the resin flow as well as the curing reaction during VARTM process.

Numerical simulations for class A surface finish in resin transfer moulding process

2012 ◽  
Vol 43 (2) ◽  
pp. 819-824 ◽  
Author(s):  
Geneviève Palardy ◽  
Pascal Hubert ◽  
Eduardo Ruiz ◽  
Mohsan Haider ◽  
Larry Lessard
Keyword(s):  
Numerical Simulations ◽  
Surface Finish ◽  
Resin Transfer Moulding ◽  
Moulding Process ◽  
Class A ◽  
Transfer Moulding

Permeability Prediction in the Impregnation Stage of Resin Transfer Moulding

2010 ◽  
Vol 160-162 ◽  
pp. 1211-1216
Author(s):  
Zhuang Liu ◽  
Xiao Qing Wu
Keyword(s):  
Stokes Equations ◽  
Approximate Model ◽  
Local Deformation ◽  
Resin Transfer Moulding ◽  
Moulding Process ◽  
2D Simulation ◽  
Macro Scale ◽  
Darcy Equations ◽  
Transfer Moulding ◽  
Meso Scale

The impregnation stage of the Resin Transfer Moulding process can be simulated by solving the Darcy equations on a mould model, with a ‘macro-scale’ finite element method. For every element, a local ‘meso-scale’ permeability must be determined, taking into account the local deformation of the textile reinforcement. This paper demonstrates that the meso-scale permeability can be computed efficiently and accurately by using meso-scale simulation tools. We discuss the speed and accuracy requirements dictated by the macro-scale simulations. We show that these requirements can be achieved for two meso-scale simulators, coupled with a geometrical textile reinforcement modeller. The first solver is based on a finite difference discretisation of the Stokes equations, the second uses an approximate model, based on a 2D simulation of the flow.

Continuous monitoring of three-dimensional resin flow through a fibre preform

2003 ◽  
Vol 34 (6) ◽  
pp. 475-480 ◽  
Author(s):  
T. Stöven ◽  
F. Weyrauch ◽  
P. Mitschang ◽  
M. Neitzel
Keyword(s):  
Continuous Monitoring ◽  
Three Dimensional ◽  
Resin Flow ◽  
Flow Through

Monitoring and modeling of part thickness evolution in vacuum infusion process

2020 ◽  
pp. 002199832096317
Author(s):  
Baris Caglar ◽  
Mert Hancioglu ◽  
E Murat Sozer
Keyword(s):  
Control Volume ◽  
Scanning System ◽  
Resin Flow ◽  
Full Field ◽  
Flow Solver ◽  
Vacuum Infusion ◽  
Structured Light Scanning ◽  
Control Volume Finite Element ◽  
Thickness Measurements ◽  
Part Thickness

The main hurdles in Vacuum Infusion (VI) are the difficulty in achieving complete mold filling and uniform part thickness. This study integrates process monitoring by full field thickness measurements and resin flow modeling that accounts for compaction and permeability characterizations of fabric reinforcements to assess the evolution of part thickness during filling and post-filling stages of VI process. A Structured Light Scanning system is used for full field thickness monitoring in experiments and a Control Volume Finite Element Method solver is implemented to couple resin flow with fabric’s compaction and permeability. Two cases are studied both experimentally and numerically. Evolutions of thickness and pressure validate the developed flow solver, its accuracy in terms of predicting fill times and fill patterns, suitability and limitations of the elastic compaction models for thickness modeling.

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