Multiple PhD positions in microstructure-mechanics relationships for structural materials at high temperaturesSubmitted by Mark Tschopp on Fri, 2012-05-04 22:01.
Multiple PhD positions are available for the fall 2012/winter 2013 semesters in microstructure-mechanics relationships for structural materials at high temperatures in the Center for Advanced Vehicular Systems (http://www.cavs.msstate.edu) at Mississippi State University. The project is funded through Air Force Office for Scientific Research (AFOSR) and will involve multiscale materials characterization, in situ SEM experiments, and high temperature mechanical testing for turbine blade structural materials (nickel-based superalloys).
Professor Gregory B. Thompson at the University of Alabama seeks post doctoral applicants for projects related to deformation modeling and oxidation in high temperature ceramic systems. The qualified candidate will use modeling to explain and help direct experimental studies. The post doc candidate will primarily contribute to a two-part program: (1) modeling the thermo-deformation modes and mechanisms in multiphase carbide and nitride materials and (2) the oxidation behavior in these same systems. The candidate will be part of a team effort to link this data to analytical microscopy characterization to elucidate those mechanisms. The ideal candidate should be versed in computational dislocation dynamics, finite element modeling, or related approaches.
I am trying to simulate the long term behaviour of the PBT (polybutyelene terephtalate) thermoplastic.
The mesh and initial stress distribution data (after ejection from the mold) were exported from Moldflow commercial program as Abaqus input (*inp) file. By default, I have already got a fist step of the simulation (linear elastic properties of polymer). What I actually need now is to simulate the long-term performance (for example in the interval of hundreds or thousands hours). It means that the real time scale is of the utmost importance for the analysis.
I am now going to model a sample with metallic glass (Cu-Zr-Ti) under stress and temperature loads. I wonder whether there is some existing database to find material properties, in particular, the creep properties with respect to temperature and stresses. Then I can use these data as input for a FE analysis.
Thank you very much!
Huang et al., PRL 98, 185501 (2007)
Watch movies at: http://netserver.aip.org/cgi-bin/epaps?ID=E-PRLTAO-98-002719
We report exceptional ductile behavior in individual double-walled and triple-walled carbon nanotubes at temperatures above 2000 C, with tensile elongation of 190% and diameter reduction of 90%, during in situ tensile-loading experiments conducted inside a high-resolution transmission electron microscope. Concurrent atomic-scale microstructure observations reveal that the superelongation is attributed to a high temperature creep deformation mechanism mediated by atom or vacancy diffusion, dislocation climb, and kink motion at high temperatures. The superelongation in double-walled and triple-walled carbon nanotubes, the creep deformation mechanism, and dislocation climb in carbon nanotubes are reported here for the first time.