College of Engineering

Mechanical Engineering Seminar

Date(s): 4/30/2013 10:00 AM - 4/30/201311:00 AM
Location: Textile Building, Room 101E Conference Room
Contact: Dr. Sankha Bhowmick sbhowmick@umassd.edu 508-999-8619
Mechanical Engineering

Mechanical Engineering (MNE) Seminar Series:
DATE: April 30, 2013
TIME: 10am–11pm
LOCATION: Textile Building, Room 101E (College of Engineering Conference Room)

SPEAKER: Mr. Michael Pinto
Graduate Student at the University of Massachusetts Dartmouth, Mechanical Engineering Department

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 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.

All are welcome! First year MNE MS students are required to attend; all other MNE students are encouraged to attend.

For more information please contact Dr. Sankha Bhowmick (sbhowmick@umassd.edu, 508-999-8619).

Thank you!


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