Hierarchical folding of elastic membranes under biaxial compressive stress

2011 ◽  
Vol 10 (12) ◽  
pp. 952-957 ◽  
Author(s):  
Pilnam Kim ◽  
Manouk Abkarian ◽  
Howard A. Stone
Author(s):  
M. E. Twigg ◽  
E. D. Richmond ◽  
J. G. Pellegrino

For heteroepitaxial systems, such as silicon on sapphire (SOS), microtwins occur in significant numbers and are thought to contribute to strain relief in the silicon thin film. The size of this contribution can be assessed from TEM measurements, of the differential volume fraction of microtwins, dV/dν (the derivative of the microtwin volume V with respect to the film volume ν), for SOS grown by both chemical vapor deposition (CVD) and molecular beam epitaxy (MBE).In a (001) silicon thin film subjected to compressive stress along the [100] axis , this stress can be relieved by four twinning systems: a/6[211]/( lll), a/6(21l]/(l1l), a/6[21l] /( l1l), and a/6(2ll)/(1ll).3 For the a/6[211]/(1ll) system, the glide of a single a/6[2ll] twinning partial dislocation draws the two halves of the crystal, separated by the microtwin, closer together by a/3.


2019 ◽  
Vol 139 (4) ◽  
pp. 190-196
Author(s):  
Shinya Urata ◽  
Yoshitaka Maeda ◽  
Hideo Nakai ◽  
Yuuya Takeuchi ◽  
Kyyoul Yun ◽  
...  

Author(s):  
Ana Claudia Dal Prá Vasata ◽  
Paulo Rogério Novak ◽  
Fabiano Ostapiv
Keyword(s):  

Alloy Digest ◽  
2015 ◽  
Vol 64 (12) ◽  

Abstract Böhler (or Boehler) M261 Extra is a precipitation hardening steel grade for plastic molds with good machinability in the precipitation hardened condition. It is used in the processing of plastics by offering high compressive stress and high wear resistance. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on heat treating and machining. Filing Code: TS-732. Producer or source: Böhler Edelstahl GmbH & Company KG. See also Alloy Digest TS-736, September 2016.


2003 ◽  
Vol 3 ◽  
pp. 52-59
Author(s):  
S.S. Komarov ◽  
N.Yu. Tsvileneva ◽  
N.I. Miskaktin

The main problems of the wave dynamics of flexible filaments and elastic membranes are solved. The reliability of the numerical algorithm proposed by the authors for calculating the elastic deformation of pneumatic structures under dynamic loading is confirmed when compared with the results of known studies obtained by analytical and numerical methods.


2005 ◽  
Vol 108-109 ◽  
pp. 181-186 ◽  
Author(s):  
Valentin V. Emtsev ◽  
Boris A. Andreev ◽  
Gagik A. Oganesyan ◽  
D.I. Kryzhkov ◽  
Andrzej Misiuk ◽  
...  

Effects of compressive stress on oxygen agglomeration processes in Czochralski grown silicon heat treated at T= 450OC, used as a reference temperature, and T= 600OC to 800OC are investigated in some detail. Compressive stresses of about P= 1 GPa lead to enhanced formation of Thermal Double Donors in materials annealed over a temperature range of T= 450OC – 600OC. It has been shown that the formation of thermal donors at T= 450OC under normal conditions and compressive stress is accompanied with loss of substitutional boron. In contrast, the concentration of the shallow acceptor states of substitutional boron in silicon annealed under stress at T≥ 600OC remains constant. An enhancement effect of thermal donor formation is gradually weakened at T≥ 700OC. The oxygen diffusivity sensitive to mechanical stress is believed to be responsible for the observed effects in heat-treated silicon.


Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2323
Author(s):  
Yubing Du ◽  
Zhiqing Zhao ◽  
Qiang Xiao ◽  
Feiting Shi ◽  
Jianming Yang ◽  
...  

To explore the basic mechanical properties and size effects of recycled aggregate concrete (RAC) with different substitution ratios of coarse recycled concrete aggregates (CRCAs) to replace natural coarse aggregates (NCA), the failure modes and mechanical parameters of RAC under different loading conditions including compression, splitting tensile resistance and direct shear were compared and analyzed. The conclusions drawn are as follows: the failure mechanisms of concrete with different substitution ratios of CRCAs are similar; with the increase in substitution ratio, the peak compressive stress and peak tensile stress of RAC decrease gradually, the splitting limit displacement decreases, and the splitting tensile modulus slightly increases; with the increase in the concrete cube’s side length, the peak compressive stress of RAC declines gradually, but the integrity after compression is gradually improved; and the increase in the substitution ratio of the recycled aggregate reduces the impact of the size effect on the peak compressive stress of RAC. Furthermore, an influence equation of the coupling effect of the substitution ratio and size effect on the peak compressive stress of RAC was quantitatively established. The research results are of great significance for the engineering application of RAC and the strength selection of RAC structure design.


Sign in / Sign up

Export Citation Format

Share Document