Latest Deformation Stories
Materials scientists have known that a metal's strength (or weakness) is governed by dislocation interactions, a messy exchange of intersecting fault lines that move or ripple within metallic crystals. But what happens when metals are engineered at the nanoscale? Is there a way to make metals stronger and more ductile by manipulating their nanostructures?Brown University scientists may have figured out a way. In a paper published in Nature, Huajian Gao and researchers from the University of...
Johns Hopkins researchers have discovered that, under the right conditions, newly developed nanocrystalline materials exhibit surprising activity in the tiny spaces between the geometric clusters of atoms called nanocrystals from which they are made.This finding, detailed recently in the journal Science, is important because these nanomaterials are becoming more ubiquitous in the fabrication of microdevices and integrated circuits. Movement in the atomic realm can affect the mechanical...
Researchers at the California Institute of Technology (Caltech) have developed a way to make some notoriously brittle materials ductile"”yet stronger than ever"”simply by reducing their size.The work, by Dongchan Jang, senior postdoctoral scholar, and Julia R. Greer, assistant professor of materials science and mechanics at Caltech, could eventually lead to the development of innovative, superstrong, yet light and damage-tolerant materials. These new materials could be used as components...
DAVIS, Calif., Jan. 22 /PRNewswire/ -- An elite panel of leading water, engineering, and environmental scientists from throughout the nation is set to meet for five days starting Sunday at the University of California at Davis to begin examining rules adopted by federal environmental and wildlife regulators to protect imperiled Delta fish species. The panel was put together by the National Academy of Sciences; the nation's most esteemed science body. U.S. Senator Dianne Feinstein,...
By stretching a foam ribbon and dissecting leaves, a mathematical model emergesApplied mathematicians dissected the morphology of the plantain lily (Hosta lancifolia), a characteristic long leaf with a saddle-like arc midsection and closely packed ripples along the edges. The simple cause of the lily's fan-like shape"”elastic relaxation resulting from bending during differential growth"”was revealed by using an equally simple technique, stretching foam ribbons.Haiyi Liang, a postdoctoral...
Crash tests often produce startling results. A new simulation process which factors in deformation during production as well as preliminary damage can predict the results of a crash test more accurately than ever.There are components that save lives: if a car rolls over during an accident, the "˜B-pillar' plays a key role. It forms one of the connections between the floor and roof of the vehicle and is designed to prevent the passenger cell from deforming too much. The materials from which...
U.S. scientists say they have created stretchable electronics that allow extreme bending and straining without a reduction in performance. University of Miami Professor Jizhou Song, Professor John Rogers at the University of Illinois and Northwestern University Professor Yonggang Huang said they developed a new design for stretchable electronics that can be wrapped around complex shapes, without a reduction in electronic function. The researchers said the new strategy is based on...
By Phillion, A B Lee, P D; Maire, E; Cockcroft, S L Semisolid tensile testing combined with X-ray microtomography (XMT) was used to characterize the development of internal damage as a function of strain in an aluminum-magnesium alloy, AA5182. Novel techniques were developed to allow the quantification of both the size evolution and orientation of the damage to determine mechanisms controlling the early stage growth and localization. During the initial stages of semisolid deformation, it was...
By Fukuta, Satoshi Asada, Fumihito; Sasaki, Yasutoshi Abstract The impact of holes drilled into air-dried wood specimens was examined in a closed heating system on the deformation fixation process of compressed wood. Holes were drilled into wood to improve steam permeability, and therein, improve manufacturing efficiency in comparison to conventional processes. The impact of drilled holes on the permeability of water in wood was also examined. The deformations of the wood specimens in the...
By Majumdar, Shrabani Bhattacharjee, D; Ray, K K The micromechanism of fatigue damage in an interstitial-free (IF) steel sheet has been studied using fully reversed stress amplitudes (Deltasigma/2). The stress-life (S-N) curve of the steel sheet has been generated, together with a series of interrupted fatigue tests at each of the chosen Deltasigma/2, to study the progress of fatigue damage in terms of the initiation, growth, and coalescence of the fatigue cracks on the surfaces of the sheet...
