scholarly journals Efficient equilibrium-based stress recovery for isogeometric laminated curved structures

2021 ◽  
pp. 113975
Author(s):  
Alessia Patton ◽  
Pablo Antolín ◽  
Josef Kiendl ◽  
Alessandro Reali
Keyword(s):  
Stress Recovery ◽  
Curved Structures

TEM investigations of surface residual stress relaxation in A12O3 and Al2O3-SiC nanocomposite

1994 ◽  
Vol 52 ◽  
pp. 628-629
Author(s):  
J. Fang ◽  
H. M. Chan ◽  
M. P. Harmer
Keyword(s):  
Residual Stress ◽  
Single Phase ◽  
Stress Relief ◽  
Stress Recovery ◽  
Surface Residual Stress ◽  
Microscopic Mechanism ◽  
Sic Particles ◽  
Annealing Procedure ◽  
The Difference ◽  
Nano Size

It was Niihara et al. who first discovered that the fracture strength of Al2O3 can be increased by incorporating as little as 5 vol.% of nano-size SiC particles (>1000 MPa), and that the strength would be improved further by a simple annealing procedure (>1500 MPa). This discovery has stimulated intense interest on Al2O3/SiC nanocomposites. Recent indentation studies by Fang et al. have shown that residual stress relief was more difficult in the nanocomposite than in pure Al2O3. In the present work, TEM was employed to investigate the microscopic mechanism(s) for the difference in the residual stress recovery in these two materials.Bulk samples of hot-pressed single phase Al2O3, and Al2O3 containing 5 vol.% 0.15 μm SiC particles were simultaneously polished with 15 μm diamond compound. Each sample was cut into two pieces, one of which was subsequently annealed at 1300° for 2 hours in flowing argon. Disks of 3 mm in diameter were cut from bulk samples.

Dynamic Analysis with Stress Recovery for Functionally Graded Materials: Numerical Simulation and Experimental Benchmarking

2014 ◽  
Vol 2 (1) ◽  
pp. 21
Author(s):  
Carlos Alberto Dutra Fraga Filho ◽  
Fernando César Meira Menandro ◽  
Rivânia Hermógenes Paulino de Romero ◽  
Juan Sérgio Romero Saenz
Keyword(s):  
Numerical Simulation ◽  
Dynamic Analysis ◽  
Functionally Graded Materials ◽  
Functionally Graded ◽  
Stress Recovery ◽  
Graded Materials

Human Stress Recovery during Exposure to Geranium Visual Stimuli

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 505b-505 ◽  
Author(s):  
Eunhee Kim ◽  
Richard H. Mattson
Keyword(s):  
Recovery Period ◽  
Visual Stimuli ◽  
Stress Recovery ◽  
Emotional States ◽  
Finger Skin Temperature ◽  
Physiological Indicators ◽  
Treatment Groups ◽  
Human Situation ◽  
Human Stress ◽  
Finger Skin

Evaluating human psychophysiological responses to plant visual stimuli provides a clearer understanding of factors within plant environments that enhance or maximize recovery from stress. Advances in physiological monitoring technology allow continuous recording and more-refined data collection of human responses to environmental stimuli. The objective of this study was to compare effects on stress recovery by exposures to geranium visual stimuli following an induced stressor, by measuring changes in physiological indicators and emotional states. One-hundred-fifty college students were randomly assigned to one of three treatment groups: red-flowering geraniums, non-flowering geraniums, or no geraniums. Each student viewed a 10-min film of a stressful human situation following a 5-min baseline, then was exposed to an assigned treatment setting during a 5-min recovery period. Continuous physiological measurements were taken of brainwave activities (EEG), skin conductance (EDR), and finger skin temperature. Self-rating scores of subjects' feelings were taken using the Zuckerman Inventory of Personal Reactions. Comparisons among treatment groups will be discussed based on gender and other demographic factors.

scholarly journals The mammalian INO80 chromatin remodeling complex is required for replication stress recovery

2014 ◽  
Vol 42 (14) ◽  
pp. 9074-9086 ◽  
Author(s):  
Ivelina Vassileva ◽  
Iskra Yanakieva ◽  
Michaela Peycheva ◽  
Anastas Gospodinov ◽  
Boyka Anachkova
Keyword(s):  
Chromatin Remodeling ◽  
Replication Stress ◽  
Stress Recovery ◽  
Chromatin Remodeling Complex

scholarly journals Transformation-Induced Relaxation and Stress Recovery of TiNi Shape Memory Alloy

Materials ◽  
2014 ◽  
Vol 7 (3) ◽  
pp. 1912-1926 ◽  
Author(s):  
Kohei Takeda ◽  
Ryosuke Matsui ◽  
Hisaaki Tobushi ◽  
Elzbieta Pieczyska
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Stress Recovery

Stress recovery behaviour of an Fe–Mn–Si–Cr–Ni–VC shape memory alloy used for prestressing

2013 ◽  
Vol 22 (12) ◽  
pp. 125037 ◽  
Author(s):  
W J Lee ◽  
B Weber ◽  
G Feltrin ◽  
C Czaderski ◽  
M Motavalli ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Stress Recovery

scholarly journals Multimodal Surface Instabilities in Curved Film–Substrate Structures

2017 ◽  
Vol 84 (8) ◽  
Author(s):  
Ruike Zhao ◽  
Xuanhe Zhao
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Numerical Simulation ◽  
Period Doubling ◽  
Tubular Structures ◽  
Modulus Ratio ◽  
Future Design ◽  
Mismatch Strain ◽  
Curved Structures ◽  
Film Substrate

Structures of thin films bonded on thick substrates are abundant in biological systems and engineering applications. Mismatch strains due to expansion of the films or shrinkage of the substrates can induce various modes of surface instabilities such as wrinkling, creasing, period doubling, folding, ridging, and delamination. In many cases, the film–substrate structures are not flat but curved. While it is known that the surface instabilities can be controlled by film–substrate mechanical properties, adhesion and mismatch strain, effects of the structures’ curvature on multiple modes of instabilities have not been well understood. In this paper, we provide a systematic study on the formation of multimodal surface instabilities on film–substrate tubular structures with different curvatures through combined theoretical analysis and numerical simulation. We first introduce a method to quantitatively categorize various instability patterns by analyzing their wave frequencies using fast Fourier transform (FFT). We show that the curved film–substrate structures delay the critical mismatch strain for wrinkling when the system modulus ratio between the film and substrate is relatively large, compared with flat ones with otherwise the same properties. In addition, concave structures promote creasing and folding, and suppress ridging. On the contrary, convex structures promote ridging and suppress creasing and folding. A set of phase diagrams are calculated to guide future design and analysis of multimodal surface instabilities in curved structures.

Shape Recovery Model of a Curved Beam Using Piezoelectric Actuation

2012 ◽  
Author(s):  
Amit Maha ◽  
Su-Seng Pang
Keyword(s):  
Shape Recovery ◽  
Shape Change ◽  
Optimal Placement ◽  
External Loading ◽  
Curved Beam ◽  
Recovery Model ◽  
Curved Structures ◽  
Beam Geometry ◽  
Circular Beam ◽  
Dynamic Shape

A thin composite curved beam under external loading is used to simulate different structures such as pressurized pipes, O-Rings etc. These products can undergo dynamic shape change and warping. A piezoelectric actuator is to be used to design for thin curved structures. Simple thin quarter circular beam geometry is analyzed with external loading at the free end. The orientation and placement of the piezoelectric material on a composite curved beam directly affects the deflection and stress applied to that beam. The optimal placement for an actuator for shape recovery was estimated.

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