For many mechanicians and materials scientists one of the most confounding things (in the ever increasing literature on carbon nanotubes) is the reported theoretical value of the nanotube elastic modulus. Depending upon the specific paper at hand, the reported numerical values range from 1 -6 TPa!
Initially posted on Applied Mechanics News on 28 April 2007.
Hot rolling from ingot is the dominant fabrication method of producing plate, sheet, and foil aluminum products. It is a striking fact that the total rolling-plant recovery of aluminum process from ingot to final products is typically about 50%. This recovery loss causes enormous amount of energy waste both as remelt energy and energy to process material that is just recycled. Assuming the annual US domestic net shipments of sheet and plate products being 10,500 million lb, 10% improvement of the hot rolling recovery will result annual savings of $126 million per year for the US domestic aluminum industry. The annual domestic energy savings would be 2.54 trillion Btu. The environmental benefits include annual reduction of 2.32 million lb SOx , 1.01 million lb NOx, 303.2 million lb CO2, 0.67 million lb of particulate, and 11000 lb VOCsd .
The fundamental inability to reduce or eliminate these recovery losses is “lack of the integrated models that relate structural properties to manufacturing processes”. Currently, processing parameters are determined by trial and error and largely based on experience. This makes it difficult to optimize the process even on the macroscale level, and almost impossible from microstructure level. Research in the following areas are desirable:
The number of registered iMechanicians has just passed 1000 today. iMechanica went "officially" online on 9 September 2006. See other numbers of iMechanica recorded today, and our evolving history.
The following are links to the FEMA (Federal Emergency Management Agency) documents:
Mitigating the threat of terrorist attacks against high occupancy buildings is a challenging task.
Chapter 1: ASSET VALUE, THREAT/HAZARD, VULNERABILITY, AND RISK
This chapter presents several methodologies for architects and engineers to quantify risk and to identify the most effective mitigation measures to achieve a desired level of protection against terrorist attacks at an acceptable cost.
C. Eberl, D. S. Gianola, R. J. Thompson (in alphabetic order)
With this contribution we would like to point to a free MATLAB tool which uses digital image correlation and tracking techniques to measure strain from a series of digital images. The code can be found on the ‘MATLAB central file exchange’ as well as the documentation, example images and some slides. We use the code on a daily basis for micro- and nanoscale measurements and present it here to be used and further developed by the community. Since it was posted at the end of september the code is now ranked place one or two in google and has been downloaded about 1000 times.
Post-doctoral position - Stochastic computational techniques to deal with uncertainties on the geometry in structural analysis
The post-doctoral student will join the pole "Structures and Couplings" of the Research Institute en Civil Engineering and Mechanics (GeM), Nantes, France (Nantes University, Ecole Centrale Nantes, CNRS UMR 6183)
We have recently been awarded a Research Project by the French National Research Agency. This project addresses theorical and numerical developments in the field of stochastic computational mechanics. The main goal of this project is to develop a robust computational technique to deal with uncertainties on the geometry in structural analysis. The proposed methodology lies on the extension of the Extended Finite Element Method (X-FEM) into the stochastic framework and the development of efficient computational techniques for solving stochastic systems.
Stent and Nitinol have revolutionized the medicine. In past decades, guidewires, stents, filters and many minimumly invasive devices and implants are made of Nitinol and they proved to be very successful.
However, the fatigue behavior of Nitinol has not been well understood. As a consequences, many stent fractures have been observed in-vivo. Below is a list of misconcepts that may contribute to the widely observed in-vivo fractures on Nitinol stents:
In continuum mechanics, it is a common practice to view a body as a field of material particles, so that the continuum mechanics is phrased as an algorithm to determine the function x(X, t), where X is the name of a particle, and x is the place of the particle at time t.
Abstracts are due April 27, 2007 for the Second International Conference on Mechanics of Biomaterials and Tissues, to take place on the Hawai’ian island of Kaua’i. Full call for papers is at the conference website. The conference is hosted by Elsevier and the launch of a new Elsevier journal on biomechanics will coincide with the timing of the meeting. (The official journal website is here.)
