Limit Analysis of Lattices Based on the Asymptotic Homogenization Method and Prediction of Size Effects in Bone Plastic Collapse

2016 ◽  
pp. 179-211 ◽  
Author(s):  
Ibrahim Goda ◽  
Francisco Dos Reis ◽  
Jean-François Ganghoffer
Keyword(s):  
Limit Analysis ◽  
Size Effects ◽  
Homogenization Method ◽  
Plastic Collapse ◽  
Asymptotic Homogenization ◽  
Asymptotic Homogenization Method

scholarly journals Size effects of mechanical metamaterials: a computational study based on a second-order asymptotic homogenization method

2020 ◽  
Author(s):  
Hua Yang ◽  
Wolfgang H. Müller
Keyword(s):  
Strain Gradient ◽  
Size Effects ◽  
Effective Strain ◽  
Homogenization Method ◽  
Second Order ◽  
Strain Gradient Theory ◽  
Asymptotic Homogenization ◽  
Aspect Ratios ◽  
Mechanical Metamaterials ◽  
Asymptotic Homogenization Method

Abstract In this paper, size effects exhibited by mechanical metamaterials have been studied. When the sizescale of the metamaterials is reduced, stiffening or softening responses are observed in experiments. In order to capture both the stiffening and softening size effects fully, a second-order asymptotic homogenization method based on strain gradient theory is used. By this method, the metamaterials are homogenized and become effective strain gradient continua. The effective metamaterial parameters including the classical and strain gradient stiffness tensors are calculated. Comparisons between a detailed finite element analysis and the effective strain gradient continua model have been made for metamaterials under different boundary conditions, different aspect ratios, different unit cells (closed or open cells) and different topologies. It shows that both stiffening and softening size effects can be captured by using the effective strain gradient continua models.

Two applications of the asymptotic homogenization method

PAMM ◽  
2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Sergey Sheshenin ◽  
Nina Artamonova ◽  
Petr Klementyev
Keyword(s):  
Homogenization Method ◽  
Asymptotic Homogenization ◽  
Asymptotic Homogenization Method

scholarly journals Assessment of models and methods for pressurized spherical composites

2016 ◽  
Vol 23 (2) ◽  
pp. 136-147
Author(s):  
David Guinovart-Sanjuán ◽  
Raffaella Rizzoni ◽  
Reinaldo Rodríguez-Ramos ◽  
Raúl Guinovart-Díaz ◽  
Julián Bravo-Castillero ◽  
...  
Keyword(s):  
Transversely Isotropic ◽  
Homogenization Method ◽  
Heterogeneous Structure ◽  
Asymptotic Homogenization ◽  
Contact Conditions ◽  
Effective Coefficients ◽  
Asymptotic Homogenization Method ◽  
Perfect Contact ◽  
Periodic Components ◽  
Radial Axis

The elastic properties of a spherical heterogeneous structure with isotropic periodic components is analyzed and a methodology is developed using the two-scale asymptotic homogenization method (AHM) and spherical assemblage model (SAM). The effective coefficients are obtained via AHM for two different composites: (a) composite with perfect contact between two layers distributed periodically along the radial axis; and (b) considering a thin elastic interphase between the layers (intermediate layer) distributed periodically along the radial axis under perfect contact. As a result, the derived overall properties via AHM for homogeneous spherical structure have transversely isotropic behavior. Consequently, the homogenized problem is solved. Using SAM, the analytical exact solutions for appropriate boundary value problems are provided for different number of layers for the cases (a) and (b) in the spherical composite. The numerical results for the displacements, radial and circumferential stresses for both methods are compared considering a spherical composite material loaded by an inside pressure with the two cases of contact conditions between the layers (a) and (b).

scholarly journals Manipulate Vibration Propagation by Anisotropic Honeycomb Structure

2018 ◽  
Vol 175 ◽  
pp. 03040
Author(s):  
Xiang Chen ◽  
Xiao-ming Wang ◽  
Yu-lin Mei
Keyword(s):  
Design Method ◽  
Honeycomb Structure ◽  
Homogenization Method ◽  
Unit Cell ◽  
Field Analysis ◽  
Acoustic Wave Propagation ◽  
Asymptotic Homogenization ◽  
Fluid Properties ◽  
Asymptotic Homogenization Method ◽  
New Type

As a new type of acoustic metamaterial, the pentamode material has extensive application prospect in controlling acoustic wave propagation because of its fluid properties. Firstly, a kind of pentamode material unit cell is designed, which is a two-dimensional honeycomb truss structure. Then, the asymptotic homogenization method is used to calculate static parameters of the unit cell, and also the influence of the geometric parameters and material composition of the unit cell on its mechanical properties is studied. Besides, based on transformation acoustics and the design method of the cylindrical cloak proposed by Norris, an acoustic cloak with isotropic density and gradient elastic modulus is constructed by periodically assembling the unit cell to guide the wave to bypass obstacles. Finally, the full displacement field analysis is carried out to prove the stealth effect of the acoustic cloak.

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