scholarly journals Microscale size effects in piezomagnetic material for the anti-plane problem

2021 ◽  
Author(s):  
Mingxiu Xu ◽  
Harm Askes ◽  
Xinchun Shang ◽  
Inna M. Gitman
Keyword(s):  
Plane Problem ◽  
Size Effects ◽  
Continuum Model ◽  
Mechanical Response ◽  
Polar Coordinates ◽  
Nonlocal Effects ◽  
Length Scales ◽  
Microstructural Effects ◽  
Gradient Effects ◽  
The Magnetic Field

AbstractA continuum model of piezomagnetic material with strain, magnetic and piezomagnetic coupling gradient effects is proposed using a variational principle in this work. This model is employed to an anti-plane problem, and a general solution is constructed in polar coordinates. Special attention is paid to microstructural effects on the magnetic and mechanical response in an infinite piezomagnetic medium with a void. It is found that the microstructural length scales have a significant influence on the mechanic and magnetic fields. The three length scales (corresponding to strain, magnetic and piezomagnetic coupling gradients) are indispensable to describe the nonlocal effects of piezomagnetism. Additionally, controlling the direction and magnitude of the magnetic field at the edge of the void can be achieved by adjusting the microstructural length scales of the piezomagnetic medium.

Multiscale Mechanics in Microelectronics: A Paradigm in Miniaturization

2004 ◽  
Vol 127 (3) ◽  
pp. 255-261 ◽  
Author(s):  
M. G. D. Geers ◽  
V. Kouznetsova ◽  
W. A. M. Brekelmans
Keyword(s):  
Mechanical Behavior ◽  
Continuum Mechanics ◽  
Size Effects ◽  
Mechanical Response ◽  
Electronic Components ◽  
Surface Layers ◽  
Component Size ◽  
Multiscale Mechanics ◽  
Microstructural Effects ◽  
Gradient Effects

This paper reviews the inherent change in the observed mechanical behavior of electronic components, structures, and multimaterials as a result of the ongoing miniaturization. In general, the size of microstructures is no longer negligible with respect to the component size in micro and submicron applications. Additionally, surface layers start to play a more prominent role in the mechanical response. Microstructural effects, macroscopically triggered gradient effects, and surface effects jointly appear and constitute the various size effects that can be observed. Classical continuum mechanics theories fail to describe these phenomena, and higher-order multiscale theories are required to arrive at an appropriate prediction of the mechanical behavior of miniaturized structures.

Experimental Analysis of Ratcheting Failure Based on the Piezomagnetic Response of X80 Pipeline Steel

2017 ◽  
Author(s):  
Sheng Bao ◽  
Shengnan Hu ◽  
Yibin Gu
Keyword(s):  
Magnetic Field ◽  
Hysteresis Loop ◽  
Mechanical Response ◽  
Pipeline Steel ◽  
Failure Process ◽  
Failure Behavior ◽  
X80 Pipeline Steel ◽  
Test Analysis ◽  
Number Of Cycles ◽  
The Magnetic Field

The objective of this research is to explore the correlation between the piezomagnetic response and ratcheting failure behavior under asymmetrical cyclic stressing in X80 pipeline steel. The magnetic field variations from cycle to cycle were recorded simultaneously during the whole-life ratcheting test. Analysis made in the present work shows that the piezomagnetic hysteresis loop evolves systematically with the number of cycles in terms of its shape and position. Corresponding to the three-stage process in the mechanical response, piezomagnetic response can also be divided into three principal stages, but the evolution of magnetic parameter is more complex. Furthermore, the loading branch and unloading branch of the magnetic field-stress hysteresis loop separate gradually from each other during ratcheting failure process, leading to the shape of hysteresis loop changes completely. Therefore, the progressive degradation of the steel under ratcheting can be tracked by following the evolution of the piezomagnetic field. And the shape transition of the hysteresis loop can be regarded as an early warning of the ratcheting failure.

Modeling of Size Effects on the Flow Stress of Type 304 Stainless Steel and Application in Coining Process

2007 ◽  
Author(s):  
Gap-Yong Kim ◽  
Muammer Koc ◽  
Jun Ni
Keyword(s):  
Grain Size ◽  
Stainless Steel ◽  
Flow Stress ◽  
Size Effect ◽  
Size Effects ◽  
Specimen Size ◽  
304 Stainless Steel ◽  
Length Scales ◽  
Type 304 ◽  
Type 304 Stainless Steel

Application of microforming in various research areas has received much attention due to the increased demand for miniature metallic parts that require mass production. For the accurate analysis and design of microforming process, proper modeling of material behavior at the micro/meso-scale is necessary by considering the size effects. Two size effects are known to exist in metallic materials. One is the “grain size” effect, and the other is the “feature/specimen size” effect. This study investigated the “feature/specimen size” effect and introduced a scaling model which combined both feature/specimen and grain size effects. Predicted size effects were compared with experiments obtained from previous research and showed a very good agreement. The model was also applied to forming of micro-features by coining. A flow stress model for Type 304 stainless steel taking into consideration the effect of the grain and feature size was developed and implemented into a finite element simulation tool for an accurate numerical analysis. The scaling model offered a simple way to model the size effect down to length scales of a couple of grains and extended the use of continuum plasticity theories to micro/meso-length scales.

Influence of surface stress on the mechanical response of nanoporous metals studied by an atomistically informed continuum model

2021 ◽  
pp. 117373
Author(s):  
Arne J. Klomp ◽  
Alexander Stukowski ◽  
Ralf Müller ◽  
Karsten Albe ◽  
Felix Diewald
Keyword(s):  
Surface Stress ◽  
Continuum Model ◽  
Mechanical Response ◽  
Nanoporous Metals

Finite size effects of ionic species sensitively determine load bearing capacities of lubricated systems under combined influence of electrokinetics and surface compliance

Soft Matter ◽  
2017 ◽  
Vol 13 (37) ◽  
pp. 6422-6429 ◽  
Author(s):  
Kaustubh Girish Naik ◽  
Suman Chakraborty ◽  
Jeevanjyoti Chakraborty
Keyword(s):  
Size Effects ◽  
Mechanical Response ◽  
Finite Size ◽  
Ionic Species ◽  
Finite Size Effects ◽  
Load Bearing

Electrokinetic effects, including finite size of ions, can significantly alter the mechanical response of lubricated systems with a deformable wall.

scholarly journals System size effects on the mechanical response of cohesive-frictional granular ensembles

2017 ◽  
Vol 140 ◽  
pp. 08007 ◽  
Author(s):  
Saurabh Singh ◽  
Ramesh Kannan Kandasami ◽  
Rupesh Kumar Mahendran ◽  
Tejas Murthy
Keyword(s):  
Size Effects ◽  
Mechanical Response ◽  
System Size

FREQUENCY SPECTRA OF FREE LATTICES AND PARTICLE SIZE EFFECTS ON THE HEAT CAPACITY OF SOLIDS

1955 ◽  
Vol 33 (6) ◽  
pp. 1079-1087 ◽  
Author(s):  
D. Patterson
Keyword(s):  
Particle Size ◽  
Heat Capacity ◽  
Low Temperature ◽  
Temperature Effect ◽  
Size Effects ◽  
Continuum Model ◽  
Free Boundaries ◽  
Frequency Spectra ◽  
Optical Modes ◽  
Effect Of Particle Size

The effect of particle size on the heat capacity of solids has been investigated using lattices with free boundaries as models. A monatomic lattice shows a low temperature effect associated with the acoustic modes. This can be compared with results obtained from a continuum model. With a diatomic lattice, however, an effect is also associated with the optical modes and is apparent at higher temperatures. The possibility that this latter effect can explain some recent experimental results is examined.

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