College of Engineering

Mechanical Engineering Seminar

Date(s): 4/12/2010 12:30 PM - 4/12/20101:30 PM
Location: Textile Building, Room 101E
Contact: Dr. Sankha Bhowmick sbhowmick@umassd.edu 508-999-8619


The Mechanical Engineering Department is pleased to announce a SEMINAR:

Monday, April 12, 2010
12:30 p.m. - 1:30 p.m.
Textile Building, Room 101E Conference Room

Speakers are:

* Mr. Sashank Padamati: "Dynamic Constitutive Behavior of Reinforced Hydrogels Inside Liquid Environment"

* Mr. Venkat Vadlamani: "Electro-Mechanical Response of Carbon Nanotube Reinforced Polymer Composites"

Advisor for both MNE Graduate Students: Dr. Vijaya Chalivendra

ABSTRACT for Mr. Sashank Padamati:
"Dynamic compressive experimentation of three different types of hydrogels potentially used for soft tissue engineering applications is conducted using a modified split Hopkinson pressure bar technique. Three kinds of hydrogels: (a) plain epoxy hydrogels, (b) epoxy hydrogels reinforced with three-dimensional polyurethane fibers with different grid sizes and (c) fumed silica nano-particles reinforced hydrogels with different weight fractions are considered in this study. The three dimensional pattern of the fibers are generated by a rapid robo-casting technique. Photo-polymerization technique was employed to fabricate nano-particles reinforced hydrogels. Different Swelling percentages of these gels are obtained by controlling mix ratio of jeffamines and epoxides. A novel liquid environment chamber was used to determine the dynamic constitutive behavior of hydrogels when immersed in water. A pulse shaping technique is used to increase the rising time of the incident pulse to generate dynamic stress equilibrium. Experiments are carried out at both quasi-static and dynamic loading conditions for different strain rates with and without water environment. Preliminary results show that the flow stress of these hydrogels decreases when they are immersed in water."

ABSTRACT for Mr. Venkat Vadlamani:
"The effect of nano-deformation, damage and growth of carbon nanotubes (CNTs) reinforced polymer composites is investigated using electro-mechanical response at different loading conditions. Three different polymer systems namely polyurethane, polyurethane reinforced with gas bubbles (that induces porosity) and polyurethane reinforced with Aluminum Silicate hollow microspheres (Cenospheres) in this study. CNTs of different weight percentages are loaded into above three polymer systems and a combination of shear mixing and ultrasonication processes are used to fabricate composites. High-resolution scanning electron microscopy and transmission electron microscopy are used to verify homogenous dispersion of CNTs in the above systems. A four-point probe method is used to measure high resolution electrical response when the above polymer systems are subjected to mechanical loads. The effect of various types of mechanical loading on different stages of deformation of test samples, onset of damage and growth will be discussed using electro-mechanical response of polymer systems."

All are welcome, and light refreshments will be served. MNE students are encouraged to attend.


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