Thglimited - Heavy Industries

title: Effects of multi-wall carbon nanotubes on the mechanical properties of polymeric nanocomposites authors: Shenoy, Kasargod Anil brabstract: The addition of carbon nanotubes into a variety of nano-composites permits the enhancement of properties like mechanical strength, conductivity and corrosion resistance thus making them more functional. In the present study, multi-wall carbon nanotubes (MWCNT) were incorporated into two different types of epoxy polymer in order to study the effect of carbon nanotubes on the mechanical properties of the polymer. The thesis work involved fabrication of nano-composite films of epoxy and MWCNT using magnetic stir-bar mixing and open mold casting process. Nanocomposite films containing different weight percentages of carbon nanotubes (0.5% to 2.0%) were prepared using the above method. Ethanol was used as the solvent to enable effective dispersion of the nanotubes into epoxy. Two different quantities of solvent (5gms and 10gms with a stirring time of 6 hrs and 12 hrs respectively) were used to evaluate the conditions required for a good dispersion of the nanotubes in the epoxy and hence to achieve a good improvement in mechanical properties of the nano-composite thus obtained. In each case the samples were subjected to uniaxial tensile testing. Finally, the design of experiments analysis was conducted which showed a substantial improvement in mechanical strength achieved with increasing weight percentages of nanotubes with the best result obtained at 12 hrs stirring of the solvent for both types of epoxy. brdescription: Thesis (M.S.) - Wichita State University, College of Engineering, Dept. of Mechanical Engineering br

Fellow Inventors; As my adventures transport me to far off continents and exotic lands of mystery, 

title: Bearing response test for the polymer matrix composite laminates: Optimization of displacement gage position authors: Narayana, Mohan Mittur brabstract: This thesis deals with composite joints with single shear tensile loading for a single piece specimen. The bearing response data from single shear test using a single piece specimen has been extensively used in the development of design allowable data. The first objective of the work was to test three different displacement gage position configurations for determining the bearing chord modulus and the 2% offset strength of composite coupons. Testing was done according to ASTM D5961: Procedure ‘C’- the standard test procedure fir finding the bearing response for polymer matrix composite laminates. The Procedure ‘C’ testing method is not yet standardized by the ASTM and there is a great deal of confusion in the extensometer position. Hence, an attempt has been made to study the variability in the chord modulus, and more importantly the 2% offset bearing strength depending on the different reference positions of the displacement gage placement. The second objective of thesis was to build a finite element (FE) model for a quasi isotropic material, to validate the FE results with experimental results, and then to conduct a set of parametric studies to study the stiffness behavior in all the three positions. The statistical analysis using Design of Experiments (DOE) of the parametric study data, identified significant factors affecting the results. brdescription: Thesis [M.S.] - Wichita State University, College of Engineering, Dept. of Mechanical Engineering br