Vacuum-Assisted Resin Transfer Moulding (VARTM): Can ultrasonic vibration decrease fill time, increase composite properties, and reduce void formation

Authors

Iulia D. Precup

Document Type

Engineering, Computing and Mathematics Article

Abstract

This study investigated the potential of ultrasonic vibration (28 kHz) to optimize the Vacuum-Assisted Resin Transfer Moulding (VARTM) process. The aim was to assess whether introducing ultrasonic vibration during the resin infusion phase could reduce fill time, improve mechanical properties, and minimize void formation in glass fibre-reinforced polyester composites. Two flexible tooling systems were compared: a reusable silicone membrane and a traditional vacuum bag. Composite plates were manufactured with and without ultrasonic vibration for both systems. Fill time was observed, and post-cured samples were subjected to mechanical testing for flexural modulus, flexural strength, and interlaminar shear strength (ILSS). Void content and morphology were analysed using X-ray micro-CT scanning.

Results showed that ultrasonic vibration reduced fill time by approximately 15% when using the silicone membrane, but inconsistent resin flow patterns hindered precise measurement. In contrast, no significant change in fill time was observed with the vacuum bag. Mechanical testing revealed a consistent decrease in all key properties for samples manufactured with the silicone membrane under vibration, with reductions in modulus, flexural strength, and ILSS. Void content remained similar across all samples; however, void morphology worsened in silicone membrane samples, with increased clustering, larger void sizes, and decreased sphericity. For vacuum bagged samples, ultrasonic vibration improved mechanical properties for tri-axial composites, with increases of 4.2% in modulus, 200-240% in flexural strength, and 4-9% in ILSS. Void morphology also improved, with smaller and more evenly distributed voids.

The study concludes that while the silicone membrane offers environmental benefits due to its reusability, it is unsuitable for vibration-assisted VARTM due to its inability to effectively transmit ultrasonic vibrations. The vacuum bag demonstrated significant potential for vibration-enhanced composite manufacturing but requires further testing with larger sample sets to achieve statistical significance.

Publication Date

2025-12

Publication Title

The Plymouth Student Scientist

Volume

18

Issue

2

ISSN

1754-2383

Deposit Date

2025-12

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

Recommended Citation

Precup, Iulia D. (2025) "Vacuum-Assisted Resin Transfer Moulding (VARTM): Can ultrasonic vibration decrease fill time, increase composite properties, and reduce void formation," The Plymouth Student Scientist: Vol. 18: Iss. 2, Article 9.
DOI: https://doi.org/10.70156/1754-2383.1533
Available at: https://pearl.plymouth.ac.uk/tpss/vol18/iss2/9