Pressure distribution in resin transfer molding with a non-rigid fiber preform

1993 ◽  
Vol 37 (1-4) ◽  
pp. 363-371 ◽  
Author(s):  
Haiqing Gong
Keyword(s):  
Pressure Distribution ◽  
Resin Transfer Molding ◽  
Fiber Preform ◽  
Transfer Molding

Formation of Microscopic Voids in Resin Transfer Molded Composites

Materials ◽  
2003 ◽  
Author(s):  
Youssef K. Hamidi ◽  
Levent Aktas ◽  
M. Cengiz Altan
Keyword(s):  
Epoxy Composite ◽  
Resin Transfer Molding ◽  
Microscopic Analysis ◽  
Void Content ◽  
Fiber Preform ◽  
Composite Part ◽  
Transfer Molding ◽  
Average Size ◽  
Induced Defects ◽  
Fiber Preforms

Performance of composite materials usually suffers from process-induced defects such as dry spots or microscopic voids. While effects of void content in molded composites have been studied extensively, knowledge of void morphology and spatial distribution of voids in composites manufactured by resin transfer molding (RTM) remains limited. In this study, through-the-thickness void distribution for a disk-shaped, E-glass/epoxy composite part manufactured by resin transfer molding is investigated. Microscopic image analysis is conducted through-the-thickness of a radial sample obtained from the molded composite disk. Voids are primarily found to concentrate within or adjacent to the fiber preforms. More than 93% of the voids are observed within the preform or in a so-called transition zone, next to a fibrous region. In addition, viod content was found to fluctuate through-the-thickness of the composite. Variation up to 17% of the average viod content of 2.15% is observed through-the-thicknesses of the eight layers studied. Microscopic analysis revealed that average size of voids near the mold surfaces is slightly larger than those located at the interior of the composite. In addition, average size of voids that are located within the fiber preform is observed to be smaller than those located in other regions of the composite. Finally, proximity to the surface is found to have no apparent effect on shape of voids within the composite.

A Numerical Study of Integrated Direct Cure Kinetics Characterization and Control for Resin Transfer Molding (RTM)

Materials ◽  
2005 ◽  
Author(s):  
Kuang-Ting Hsiao
Keyword(s):  
Control System ◽  
Numerical Study ◽  
Resin Transfer Molding ◽  
Cure Kinetics ◽  
Mold Temperature ◽  
Fiber Preform ◽  
Transfer Molding ◽  
Cure Cycle ◽  
Numerical Case Study

In Resin Transfer Molding (RTM), the fiber preform is first placed inside a mold cavity and is subsequently impregnated with liquid resin. After mold filling, the resin starts to cure and bind the fiber preform into a solid composite part. The cure cycle will affect the residual stress built during RTM and must be controlled. Traditionally, the cure cycle control is achieved through three steps: offline resin cure kinetics characterization, offline cure cycle optimization, and mold temperature control. Different from other traditional cure cycle control approaches, this paper presents an investigation to achieve an integrated cure kinetics characterization-control system by combining a newly developed direct cure kinetics characterization method with online cure cycle optimization. A methodology to seamlessly combine these components for a practicable online cure characterization-control system will be presented and demonstrated by a numerical case study. The accuracy and reliability of this methodology will be examined and discussed based on the results of the numerical case study.

Three-dimensional flow simulation of resin transfer molding utilizing multilayered fiber preform

2009 ◽  
Vol 114 (3) ◽  
pp. 1803-1812 ◽  
Author(s):  
Seung Hwan Lee ◽  
Mei Yang ◽  
Young Seok Song ◽  
Seong Yun Kim ◽  
Jae Ryoun Youn
Keyword(s):  
Resin Transfer Molding ◽  
Three Dimensional ◽  
Flow Simulation ◽  
Fiber Preform ◽  
Three Dimensional Flow ◽  
Transfer Molding ◽  
Dimensional Flow

scholarly journals A Study on Slip Behavior of Fiber Preform by High Speed Resin Flow in High Pressure Resin Transfer Molding

2014 ◽  
Vol 27 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Jong-Moo Ahn ◽  
Dong-Gi Seong ◽  
Won-Oh Lee ◽  
Moon-Kwang Um ◽  
Jin-Ho Choi
Keyword(s):  
High Pressure ◽  
High Speed ◽  
Resin Transfer Molding ◽  
Resin Flow ◽  
Fiber Preform ◽  
Transfer Molding

Resin Velocity and Pressure Distribution in Resin Transfer Molding of a Composite Cylinder

2005 ◽  
Author(s):  
Hossein Golestanian
Keyword(s):  
Pressure Distribution ◽  
Numerical Models ◽  
Resin Transfer Molding ◽  
Fiber Types ◽  
Composite Cylinder ◽  
Sharp Drop ◽  
Transfer Molding ◽  
Flow Problems ◽  
Finite Element Software ◽  
Rtm Process

Resin Transfer Molding (RTM) process in the manufacturing of a composite cylinder is investigated. Resin flow in the woven fiber mat is modeled as flow through porous media to determine resin velocity and pressure distribution along the part. Five-harness carbon and eight-harness fiberglass mats with epoxy resin composites are investigated. Fiber mat permeability for the two fiber types are determined experimentally. These values are then employed in numerical models to simulate the injection cycle of the RTM process. ANSYS finite element software is used to perform the analysis. The results indicate that resin velocity in fiberglass mats is almost six times the velocity in carbon fiber mats. This is due to the higher permeability of fiberglass mats. The sharp drop in the resin velocity into carbon fibers indicates that flow problems will exist in the manufacturing of large carbon/epoxy parts with RTM processes.

scholarly journals Prediction of Defect Formation during Resin Impregnation Process through a Multi-Layered Fiber Preform in Resin Transfer Molding by a Proposed Analytical Model

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2055 ◽  
Author(s):  
Dong Seong ◽  
Shino Kim ◽  
Doojin Lee ◽  
Jin Yi ◽  
Sang Kim ◽  
...  
Keyword(s):  
Defect Formation ◽  
Resin Transfer Molding ◽  
Compressive Behavior ◽  
Fiber Preform ◽  
Transfer Molding ◽  
Resin Impregnation ◽  
Reinforced Composite ◽  
Fiber Deformation ◽  
Occurrence Type ◽  
Fiber Preforms

It is very important to predict any defects occurring by undesired fiber deformations to improve production yields of resin transfer molding, which has been widely used for mass production of carbon fiber reinforced composite parts. In this study, a simple and efficient analytic scheme was proposed to predict deformations of a multi-layered fiber preform by comparing the forces applied to the preform in a mold of resin transfer molding. Friction coefficient of dry and wet states, permeability, and compressive behavior of unidirectional (UD) and plain woven (PW) carbon fabrics were measured, which were used to predict deformations of the multi-layered fiber preforms with changing their constitution ratios. The model predicted the occurrence, type, and position of fiber deformation, which agreed with the experimental results of the multi-layered preforms.

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