College of Engineering

Mechanical Engineering MS Thesis Defense of Michael Pinto

Date(s): 5/16/2013 10:00 AM - 5/16/201312:00 PM
Location: Charlton College of Business, Room 115 (CCB-115)
Contact: Dr. Vijaya Chalivendra vchalivendra@umassd.edu 508-910-6572
Mechanical Engineering

The Mechanical Engineering Department is pleased to announce the MS THESIS DEFENSE of Mr. MICHAEL PINTO on Thursday, May 16, 2013 from 10am–12pm in the Charlton College of Business, Room 115 (CCB-115).

TOPIC: Improving the Strength and Service Life of Laminated Jute/Epoxy Composites for Structural Applications.

ABSTRACT: This study examines the effects of preform architecture, surface treatment, and z-directional reinforcement on the performance of jute/epoxy laminated composites. Alkali and silane coupling treatments were applied to the reinforcement using techniques adapted from recent publications. Two silane agents, APTES and Dow Corning Z-6173, were compared for their effect on the moisture and epoxy affinity of jute using wicking tests. These test showed Dow Corning Z-6173 produced yarn with zero water wicking and increased epoxy wicking, leading to the selection of this coupling agent for use on fabric reinforcement. Constituent analysis showed that traditional hand-layup fabrication method resulted in composites with unacceptably high void content (~15%). For this reason, the Vacuum Infusion (VI) method was employed and optimized for use with natural fibers. The addition of a pre-compaction and deadweight compaction step resulted in composites with near-zero void content and acceptable fiber volume fraction (35-50%). This method was used to fabricate composites with both plain weave and unidirectional reinforcement. Mechanical testing showed surface treatments increased Tensile Modulus by 36% and Fracture Toughness while moderately decreasing Tensile Strength and ILSS. SEM examination of the fracture surfaces confirmed these changes were the result of improved interfacial adhesion. Unidirectional preforms were found to result in composites with increased Tensile Strength and Modulus by 34% and 40% respectively, but lower ILSS and Fracture Toughness as compared to plain weave preforms. This was attributed to reduced fabric crimp in addition to reduced inter-ply interaction. The addition of z-direction reinforcement was shown to increase Mode-I Fracture Toughness by 200% and increased ILSS at the cost of decreased Tensile Strength and Modulus. The water absorption of the fabricated jute/epoxy composites was evaluated using water immersion testing. It was found that moisture absorption was reduced by 60% as a result of fiber surface treatment.

ADVISOR: Dr. Vijaya Chalivendra

COMMITTEE MEMBERS: Dr. Vijaya Chalivendra, Dr. Yong Kim, Dr. John Rice

Open to the public. All MNE students are encouraged to attend. For more information please contact Dr. Vijaya Chalivendra (vchalivendra@umassd.edu, 508-910-6572). Thank you.


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