Fast method to monitor the flow front and control injection parameters in resin transfer molding using pressure sensors

Fratta, Claudio Di; Koutsoukis, Grigorios; Klunker, Florian; Ermanni, Paolo

doi:10.1177/0021998315614994

Cited by 26 publications

(24 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…18,19 Void content percentage increased with higher fiber contents. Such increase in fiber contents reduces the composite's permeability, as observed by Frata et al 20 This explains the fact that resin flow is reduced in AD6 composite, decreasing matrix volume and increasing void contents from regions 2 to 5. Table 3 shows mechanical and dynamic mechanical properties of the composites.…”

Section: Resultsmentioning

confidence: 61%

Mechanical and ballistic analysis of aramid/vinyl ester composites

Pagnoncelli

Piroli

Romanzini

et al. 2017

Journal of Composite Materials

View full text Add to dashboard Cite

This study focused on evaluating mechanical and dynamic-mechanical properties of polyaramid/vinyl ester composites, as a function of the fiber content. Furthermore, split Hopkinson pressure bar technique and V 50 Ballistic limit tests were performed. Composites were prepared by resin transfer molding (RTM) with different fiber content, samples being identified as AD4, AD5 and AD6 (with 4, 5 and 6 polyaramid layers, respectively). Initially, fiber, void and matrix contents were calculated and statistically analyzed, in different regions of the composites. Mechanical and dynamical mechanical properties of the composites were improved by using higher fiber content. For example, impact strength of AD6 composite was 35% higher than AD4. Moreover, increase in the fiber content promoted an increase in tenacity and stress of the composites, in the same strain rate. Velocity limit in AD6 sample was estimated in ballistics tests and it was concluded that the composite obtained could accomplish the level I requisites of ballistic protection with V 50 of 304 m.s À1 .

show abstract

Section: Resultsmentioning

confidence: 61%

Mechanical and ballistic analysis of aramid/vinyl ester composites

Pagnoncelli

Piroli

Romanzini

et al. 2017

Journal of Composite Materials

View full text Add to dashboard Cite

show abstract

“…Möller et al [26] used an approach based on the integration of the fluidity until gel time, in order to study the processability of different polymers by resin infusion. Simplified procedures have also been proposed for control of the injection and curing stages as well as for online assessment of laminate quality [27,28]. However, no systematic, robust, and efficient methodology has been devised yet to optimize the mold features and the whole injection process concurrently.…”

Section: State Of the Artmentioning

confidence: 99%

A Dimensionless Characteristic Number for Process Selection and Mold Design in Composites Manufacturing: Part I—Theory

et al. 2020

Self Cite

View full text Add to dashboard Cite

The present article introduces a dimensionless number devised to assist composite engineers in the fabrication of continuous fiber composites by Liquid Composite Molding (LCM), i.e., by injecting a liquid polymer resin through a fibrous reinforcement contained in a closed mold. This dimensionless number is calculated by integrating the ratio of the injection pressure to the liquid viscosity over the cavity filling time. It is hereby called the “injectability number” and provides an evaluation of the difficulty to inject a liquid into a porous material for a given part geometry, permeability distribution, and position of the inlet gate. The theoretical aspects behind this new concept are analyzed in Part I of the article, which demonstrates the invariance of the injectability number with respect to process parameters like constant and varying injection pressure or flow rate. Part I also details how process engineers can use the injectability number to address challenges in composite fabrication, such as process selection, mold design, and parameter optimization. Thanks to the injectability number, the optimal position of the inlet gate can be assessed and injection parameters scaled to speed up mold design. Part II of the article completes the demonstration of the novel concept by applying it to a series of LCM process examples of increasing complexity.

show abstract

“…Figure 7 illustrates the investigated cavity geometry and the simulated filling, which reproduces an injection through a central inlet gate by RTM. Thin shell elements are used in the simulations, which, unlike the other tests presented in this article, are carried out using the software COMSOL Multiphysics [9][10][11]. A preform with porosity of 0.5 and anisotropic permeability is considered: the principal permeability values are K 1 = 5 × 10 −10 m 2 and K 2 = 2.5 × 10 −10 m 2 , aligned along the x and y axes respectively.…”

Section: Vehicle Hoodmentioning

confidence: 99%

A Dimensionless Characteristic Number for Process Selection and Mold Design in Composites Manufacturing: Part II—Applications

et al. 2020

Self Cite

View full text Add to dashboard Cite

The dimensionless “injectability number” was devised to assist composite engineers in the fabrication of continuous fiber composites by Liquid Composite Molding (LCM), i.e., by injecting a liquid polymer resin through a fibrous reinforcement contained in a mold cavity. Part I of this article introduced the injectability number as the integral of the ratio of the injection pressure to the resin viscosity over the cavity filling time and analyzed the theoretical aspects behind this new concept. For a given mold configuration and reinforcement material characteristics, the invariance of the injectability number with regard to process parameters was demonstrated, and an initial verification in unidirectional injection cases was conducted. Part II completes the analysis by evaluating the injectability number in more complex application cases, confirming its invariance properties. The investigation, which was carried out using numerical simulations of different LCM processes and injection strategies, examined the fabrication of various composite parts: a rectangular laminate, a hood for automotive applications, a reservoir box and a fuselage section for the aerospace industry. The results indicate that more efficient injection strategies lead to lower values of the injectability number, thus enabling the use of this dimensionless number as a tool to assess the difficulty to manufacture a given part by LCM as well as to guide process selection and compare different mold configurations.

show abstract

Fast method to monitor the flow front and control injection parameters in resin transfer molding using pressure sensors

Cited by 26 publications

References 30 publications

Mechanical and ballistic analysis of aramid/vinyl ester composites

Mechanical and ballistic analysis of aramid/vinyl ester composites

A Dimensionless Characteristic Number for Process Selection and Mold Design in Composites Manufacturing: Part I—Theory

A Dimensionless Characteristic Number for Process Selection and Mold Design in Composites Manufacturing: Part II—Applications

Contact Info

Product

Resources

About