Effect of global constraint on the mechanical behavior of gradient materials

2021 ◽  
pp. 141963
Author(s):  
Jingran Yang ◽  
Le Xu ◽  
Hongliang Gao ◽  
Xingfu Li ◽  
Hongjiang Pan ◽  
...  
Keyword(s):  
Mechanical Behavior ◽  
Global Constraint ◽  
Gradient Materials

Stability analysis of FGM microgripper subjected to nonlinear electrostatic and temperature variation loadings

2016 ◽  
Vol 23 (2) ◽  
pp. 199-207 ◽  
Author(s):  
Reza Jahanghiry ◽  
Rajab Yahyazadeh ◽  
Naser Sharafkhani ◽  
Vahid A. Maleki
Keyword(s):  
Wear Resistance ◽  
Mechanical Behavior ◽  
Temperature Variation ◽  
Linearization Method ◽  
System Stability ◽  
Dc Voltage ◽  
Gradient Materials ◽  
Functionally Gradient ◽  
The Galerkin Method ◽  
Geometrical Dimensions

AbstractConsidering the desired characteristics of functionally gradient materials (FGM), such as good thermal and wear resistance, this paper investigates the mechanical behavior of FGM microgripper under DC voltage and temperature variation. It is assumed that the two microbeams of the FGM microgripper are mounted symmetrically against each other, and the volume of ceramic varies exponentially with microbeam thickness. The nonlinear equations governing the static and dynamic deflection of microbeams due to the application of DC voltage and temperature variation are derived and solved using the step-by-step linearization method and the Galerkin method. In previous studies, the mechanical behavior of a microgripper with homogenous and the same material has been investigated; in this paper, the response and stability of the FGM microgripper against DC voltage and temperature variation are investigated. Also, the effect of geometrical dimensions, ceramic volume, and its variations with microbeam thickness on the mechanical behavior and system stability is studied.

Application of TEM to Deformation, Wear, and Fracture of Ceramics

1974 ◽  
Vol 32 ◽  
pp. 472-473
Author(s):  
B. J. Hockey
Keyword(s):  
Wear Resistance ◽  
High Temperature ◽  
Mechanical Behavior ◽  
Brittle Materials ◽  
High Temperature Strength ◽  
Wide Range ◽  
Corrosive Environments ◽  
Further Development

Ceramics, such as Al2O3 and SiC have numerous current and potential uses in applications where high temperature strength, hardness, and wear resistance are required often in corrosive environments. These materials are, however, highly anisotropic and brittle, so that their mechanical behavior is often unpredictable. The further development of these materials will require a better understanding of the basic mechanisms controlling deformation, wear, and fracture.The purpose of this talk is to describe applications of TEM to the study of the deformation, wear, and fracture of Al2O3. Similar studies are currently being conducted on SiC and the techniques involved should be applicable to a wide range of hard, brittle materials.

The influence of the addition of ground olive stone on the thermo-mechanical behavior of compressed earth blocks

2020 ◽  
Vol 108 (2) ◽  
pp. 203
Author(s):  
Samia Djadouf ◽  
Nasser Chelouah ◽  
Abdelkader Tahakourt
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Mechanical Behavior ◽  
Agricultural Waste ◽  
Hydraulic Press ◽  
Dry Density ◽  
Olive Stone ◽  
Compressed Earth Blocks ◽  
Clay Matrix ◽  
Earth Blocks

Sustainable development and environmental challenges incite to valorize local materials such as agricultural waste. In this context, a new ecological compressed earth blocks (CEBS) with addition of ground olive stone (GOS) was proposed. The GOS is added as partial clay replacement in different proportions. The main objective of this paper is to study the effect of GOS levels on the thermal properties and mechanical behavior of CEB. We proceeded to determining the optimal water content and equivalent wet density by compaction using a hydraulic press, at a pressure of 10 MPa. The maximum compressive strength is reached at 15% of the GOS. This percentage increases the mechanical properties by 19.66%, and decreases the thermal conductivity by 37.63%. These results are due to the optimal water responsible for the consolidation and compactness of the clay matrix. The substitution up to 30% of GOS shows a decrease of compressive strength and thermal conductivity by about 38.38% and 50.64% respectively. The decrease in dry density and thermal conductivity is related to the content of GOS, which is composed of organic and porous fibers. The GOS seems promising for improving the thermo-mechanical characteristics of CEB and which can also be used as reinforcement in CEBS.

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