Uncertainty Modeling of Residual Stress Development in Polymeric Composites Manufactured With Resin Transfer Molding Process

2007 ◽  
Author(s):  
Kuang-Ting Hsiao
Keyword(s):  
Residual Stress ◽  
Resin Transfer Molding ◽  
Parametric Uncertainty ◽  
Polymeric Composite ◽  
Cure Kinetics ◽  
Polymeric Composites ◽  
Molding Process ◽  
Stress Development ◽  
Transfer Molding ◽  
Rtm Process

Resin Transfer Molding (RTM) is an advanced process to manufacture high quality thermoset polymeric composites. The quality of the composite depends on the resin infusion stage and the cure stage during the RTM process. The resin curing is a complex exothermic process which involves resin mechanical property evolution, resin volume shrinkage, thermal expansion, heat transfer, and chemical reaction. Since the fibers and resin have many differences in their physical properties, the composite cure stage inevitably introduces the undesired residual stress to the composite parts. As the residual stress could sometimes generate local matrix failure or degrade the performance of the composite, it is important to model and minimize the residual stress. This paper presents a model to predict the residual stress development during the composite cure process. By slightly disturbing the manufacturing parameters such as the mold heating cycle and the cure kinetics of polymer, the variations of residual stress development during the RTM process can be modeled and compared. A parametric uncertainty study of the residual stress development in the polymeric composite manufactured with RTM will be performed and discussed.

Preparation and Properties of a Novel Water Soluble Core Material for the Resin Transfer Molding Process

2011 ◽  
Vol 306-307 ◽  
pp. 844-847
Author(s):  
Quan Zhou Li ◽  
Xiao Qing Wu
Keyword(s):  
Compressive Strength ◽  
Resin Transfer Molding ◽  
Water Soluble ◽  
Core Material ◽  
Molding Process ◽  
Transfer Molding ◽  
The Core ◽  
Rtm Process ◽  
Binder Solution ◽  
Core Materials

A novel water soluble core material composed of alumina, quartz sand, kaolin, gypsum powder and the solution of binders was prepared. The influence of different mass concentration of Polyethylene Glycol (PEG) binder solution and sodium silicate compounded (SS) binders solution on water soluble performance and compressive strength of the core materials was investigated, respectively. The results show that the compressive strength and solubility rate of the core materials, with the concentration of 30% of SS binders solution, are 1.023MPa and 0.24g/s respectively, which is satisfied for the requirements of Resin Transfer Molding (RTM) process completely.

Effects of Weirs on the Resin Transfer Molding Process

2001 ◽  
Author(s):  
Kiran M. D’Silva ◽  
Su-Seng Pang ◽  
Kurt C. Schulz
Keyword(s):  
Glass Fibers ◽  
Resin Transfer Molding ◽  
Mold Filling ◽  
Laminated Plates ◽  
Molding Process ◽  
Outlet Port ◽  
Transfer Molding ◽  
Inlet Port ◽  
Rtm Process ◽  
Filling Time

Abstract Low mold filling time and improper fiber wetting are the main problems faced by the manufacturers applying the Resin Transfer Molding (RTM) process. The objective of this work was to minimize these problems and to study the effect of weirs on the RTM process. A mold was designed such that the lower mold plate contains two weirs, one at the resin inlet port and the other at the outlet port. The purpose of adding the weirs is to provide a continuous inlet stream near the resin inlet port and to cause backpressure near the outlet port to induce complete mold filling. Laminated plates were prepared using glass fibers and epoxy resin (combination of EPON resin-862 and curing agent W). The test parameters investigated, such as void contents, dry spots and mold filling time, were compared with those of samples that were prepared without the use of weirs. It was found that the presence of weirs resulted in significant elimination of dry spots, minimization of void contents and a reduction in mold filling time. As a result, the cost required to manufacture composite parts can be reduced by the use of weirs. In addition to the experimental investigation, a computer simulation (using LCMFLOT software) of resin flow inside the mold cavity was conducted. Many simulations were run in order to optimize the height and shape of the weir. Rectangular weirs of height 2.54 mm showed minimum mold fill time. It was found that the results obtained from the experimental work and flow simulations are in good agreement. Based on this work, it is evident that complex parts can be produced in less cycle time if weirs are positioned at appropriate locations.

scholarly journals Embedded Based Real-Time Monitoring in the High-Pressure Resin Transfer Molding Process for CFRP

2019 ◽  
Vol 9 (9) ◽  
pp. 1795 ◽  
Author(s):  
Kim ◽  
Kim ◽  
Hwang ◽  
Kim
Keyword(s):  
High Pressure ◽  
Real Time ◽  
Process Monitoring ◽  
High Speed ◽  
Resin Transfer Molding ◽  
Time Signal ◽  
Process Variables ◽  
Molding Process ◽  
Transfer Molding ◽  
Rtm Process

Carbon Fiber Reinforced Plastics (CFRP) is a material developed for its high strength and light weight in a broad variety of industries including aerospace, automotive, and leisure. Due to the rapid molding cycle time, high-pressure resin transfer molding (HP-RTM) processes are prone to molding defects and susceptible to various process variables such as the resin injection rate, pressure and temperature in the mold, vacuum, end-gap, pressing force, and binder. In recent years, process monitoring technology with various sensors has been applied to stabilize the HP-RTM process and control process variables. The field-programmable gate array (FPGA) based embedded monitoring system proposed in this study enabled high-speed real-time signal processing with multiple sensors, namely pressure, temperature, and linear variable differential transformer (LVDT), and proved feasibility in the field. In the HP-RTM process, the impregnation and curing of the resin were predicted from the cavity pressure and temperature variations during the injection and curing stages. In addition, the thickness of the CFRP specimen was deduced from the change in the end-gap through the detection of the LVDT signal. Therefore, the causes of molding defects were analyzed through process monitoring and the influence of molding defects on the molding quality of CFRP was investigated.

Effect of CaCO3 Content in Resin Transfer Molding Process

2013 ◽  
Vol 334-335 ◽  
pp. 188-192 ◽  
Author(s):  
Iran Rodrigues de Oliveira ◽  
Sandro Campos Amico ◽  
F. Ferreira Luz ◽  
R. Barcella ◽  
V.M. França Bezerra ◽  
...  
Keyword(s):  
Porous Media ◽  
Low Cost ◽  
Resin Transfer Molding ◽  
Molding Process ◽  
Transfer Molding ◽  
Advanced Composite ◽  
Rtm Process ◽  
Advanced Composite Materials ◽  
Closed Mold ◽  
The Individual

Composite material can be defined as a combination of two or more materials on a macroscale to form a useful material, often showing properties that none of the individual independent components shows. Resin Transfer Molding (RTM) is one of the most widely known composite manufacturing technique of the liquid molding family, being extensively studied and used to obtain advanced composite materials comprised of fibers embedded in a thermoset polymer matrix. This technique consists in injecting a resin pre-catalysed thermosetting in a closed mold containing a dry fiber preform, where the resin is impregnated. The aim of this study is to investigate the effect caused by the use of CaCO3filled resin on the characteristics of the RTM process. Several experiments were conducted using glass fiber mat and polyester resin molded in a RTM system with cavity dimensions of 320 x 150 x 3.6 mm, at room temperature, and different CaCO3content (0, 10, 20, 30 and 40% in weight). The results show that the use of filled resin with CaCO3influences the resin viscosity and the porous media permeability, making it difficult to fill the porous media during the molding process, however it is possible to make composite with a good quality and low cost.

On Computer Aided Formation Framework for Composite Material

2013 ◽  
Vol 710 ◽  
pp. 775-778
Author(s):  
Juan Wang ◽  
Si Yu Lai
Keyword(s):  
Process Integration ◽  
Resin Transfer Molding ◽  
Object Oriented Programming ◽  
System Structure ◽  
Planning System ◽  
Computer Assisted ◽  
Molding Process ◽  
Transfer Molding ◽  
Component Technique ◽  
Rtm Process

The composite molding process design systems are developed on specific manufacturing resources or specific environment whenever at home and abroad, which enjoys a poor versatility. We built the system structure and flow for composite process integration framework after the computer-assisted resin transfer molding software has been developed. Then, studied the template-based data structure and established the model that can form a CAPP application system rapidly; developed a three levels similar cases retrieval structure based on part level, shape level and feature level; realized the customization of process card by adopting the excel template method. Finally, a resin transfer molding (RTM) process planning system is customized by object oriented programming (OOP) and component technique to verity the validity and feasibility of the integrating framework.

Cure Kinetics of High Performance Epoxy Molding Compounds

2014 ◽  
Vol 1024 ◽  
pp. 151-154
Author(s):  
Chean Cheng Su ◽  
Cheng Fu Yang ◽  
Chien Huan Wei
Keyword(s):  
Kinetic Model ◽  
High Performance ◽  
Resin Transfer Molding ◽  
Cure Kinetics ◽  
Molding Process ◽  
Transfer Molding ◽  
Molding Compounds ◽  
Higher Temperature ◽  
Kinetics Of ◽  
Rubber State

The reaction of EMCs with the triphenylphosphine-1,4-benzoquinone (TPP-BQ) latent catalyst also had a higher temperature sensitivity compared to the reaction of EMCs with triphenylphosphine (TPP) catalyst. In resin transfer molding, EMCs containing the TPP-BQ thermal latency accelerator are least active at a low temperature. Consequently, EMCs have a low melt viscosity before gelation, and the resins and filler are evenly mixed in the kneading process. Additionally, the rheological property, flowability, is increased before the EMC form a network structure in the molding process. The proposed kinetic model adequately describes curing behavior in EMCs cured with two different organophosphine catalysts up to the rubber state in the progress of curing.

scholarly journals A Conceptional Approach of Resin-Transfer-Molding to Rosin-Sourced Epoxy Matrix Green Composites

Aerospace ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 5
Author(s):  
Sicong Yu ◽  
Xufeng Zhang ◽  
Xiaoling Liu ◽  
Chris Rudd ◽  
Xiaosu Yi
Keyword(s):  
Composite Laminates ◽  
Resin Transfer Molding ◽  
High Viscosity ◽  
Ramie Fiber ◽  
Liquid Composite Molding ◽  
Curing Agent ◽  
Molding Process ◽  
Transfer Molding ◽  
Low Viscosity ◽  
Composite Molding

In this concept-proof study, a preform-based RTM (Resin Transfer Molding) process is presented that is characterized by first pre-loading the solid curing agent onto the preform, and then injecting the liquid nonreactive resin with an intrinsically low viscosity into the mold to infiltrate and wet the pre-loaded preform. The separation of resin and hardener helped to process inherently high viscosity resins in a convenient way. Rosin-sourced, anhydrite-cured epoxies that would normally be regarded as unsuited to liquid composite molding, were thus processed. Rheological tests revealed that by separating the anhydrite curing agent from a formulated RTM resin system, the remaining epoxy liquid had its flowtime extended. C-scan and glass transition temperature tests showed that the preform pre-loaded with anhydrite was fully infiltrated and wetted by the liquid epoxy, and the two components were diffused and dissolved with each other, and finally, well reacted and cured. Composite laminates made via this approach exhibited roughly comparable quality and mechanical properties with prepreg controls via autoclave or compression molding, respectively. These findings were verified for both carbon and ramie fiber composites.

Development of resin transfer molding process using scaling down strategy

2013 ◽  
Vol 35 (9) ◽  
pp. 1683-1689 ◽  
Author(s):  
Raghu Raja Pandiyan Kuppusamy ◽  
Swati Neogi
Keyword(s):  
Resin Transfer Molding ◽  
Molding Process ◽  
Transfer Molding ◽  
Scaling Down

scholarly journals Resin transfer molding process: a numerical and experimental investigation

2013 ◽  
Vol 7 (2) ◽  
pp. 125-136 ◽  
Author(s):  
Iran de Oliveira ◽  
Sandro Amico ◽  
Jeferson Souza ◽  
Antonio de Lima
Keyword(s):  
Experimental Investigation ◽  
Resin Transfer Molding ◽  
Molding Process ◽  
Transfer Molding
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