scholarly journals Finite element prediction of effective elastic properties of interpenetrating phase composites with architectured 3D sheet reinforcements

2016 ◽  
Vol 83 ◽  
pp. 169-182 ◽  
Author(s):  
Ahmed S. Dalaq ◽  
Diab W. Abueidda ◽  
Rashid K. Abu Al-Rub ◽  
Iwona M. Jasiuk
Keyword(s):  
Finite Element ◽  
Elastic Properties ◽  
Effective Elastic Properties ◽  
Finite Element Prediction ◽  
Interpenetrating Phase Composites

scholarly journals 3D finite-element modeling of effective elastic properties for fracture density and multiscale natural fractures

2021 ◽  
Vol 18 (4) ◽  
pp. 567-582
Author(s):  
Shikai Jian ◽  
Li-Yun Fu ◽  
Chenghao Cao ◽  
Tongcheng Han ◽  
Qizhen Du
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Elastic Properties ◽  
Least Square ◽  
P Wave ◽  
Fracture Density ◽  
Equivalent Stiffness ◽  
Natural Fractures ◽  
Effective Elastic Properties ◽  
Element Modeling

Abstract Natural fractures are usually multiscale in size, orientations and distribution, resulting in complex anisotropic characteristics. Analytical methods for quantifying the associated effective elastic properties are based on some assumptions, such as dilute fracture concentration and regular-shaped fractures, which do not occur in actual reservoirs. Here, we conduct anisotropic finite-element modeling of effective elastic properties of complex fractured rocks using the least-square fitting method. The algorithm is developed for a 3D case and validated by classical effective medium theories for models with different fracture densities. The results of the 3D numerical method agree well with the theoretical predictions at low fracture density. The model also considers the interactions among fractures to calculate equivalent stiffness tensors at high fracture density. Three 2D fracture models are simulated to demonstrate the basic behavior of stress interactions and their effect on the overall elasticity under different fracture densities. We applied the developed model to 3D natural fractures built from a real outcrop, and we found that the fracturing pattern significantly affects the effective anisotropy properties. The resultant P-wave phase velocities as functions of the incidence angle and frequency are anisotropic. This study provides a great potential to calculate equivalent stiffness tensors and anisotropic properties of 3D multiscale natural fractures.

scholarly journals Finite element modelling of the effective elastic properties of partially saturated rocks

2008 ◽  
Vol 34 (6) ◽  
pp. 647-657 ◽  
Author(s):  
Dina Makarynska ◽  
Boris Gurevich ◽  
Radim Ciz ◽  
Christoph H. Arns ◽  
Mark A. Knackstedt
Keyword(s):  
Finite Element ◽  
Elastic Properties ◽  
Finite Element Modelling ◽  
Effective Elastic Properties ◽  
Element Modelling ◽  
Partially Saturated

Analytical, Numerical, and Experimental Studies of Effective Elastic Properties of Periodically Perforated Materials

1996 ◽  
Vol 118 (1) ◽  
pp. 43-48 ◽  
Author(s):  
S. A. Meguid ◽  
A. L. Kalamkarov ◽  
J. Yao ◽  
A. Zougas
Keyword(s):  
Finite Element ◽  
Elastic Properties ◽  
Experimental Studies ◽  
Perforated Plate ◽  
Element Model ◽  
Asymptotic Homogenization ◽  
Element Analysis ◽  
Effective Elastic Properties ◽  
Uniaxial Testing ◽  
Circular Holes

Comprehensive analytical, finite element analysis and experimental studies are made of the interaction between closely spaced multiple circular holes. The analytical model utilizes the technique of asymptotic homogenization and the complex variable method to obtain explicit expressions for the effective elastic properties of a completely perforated plate under uniaxial loading. The analytical predictions are then compared with a finite element model and the results of both techniques are verified experimentally using uniaxial testing under controlled conditions. The findings of the present work are also compared with earlier solutions and efforts are made to highlight inconsistencies and limitations of the three techniques.

Micromechanical modeling of 3D printable interpenetrating phase composites with tailorable effective elastic properties including negative Poisson's ratio

2017 ◽  
Vol 02 (04) ◽  
pp. 1750015 ◽  
Author(s):  
L. Ai ◽  
X.-L. Gao
Keyword(s):  
Elastic Properties ◽  
Effective Properties ◽  
Matrix Material ◽  
Micromechanical Model ◽  
Micromechanical Modeling ◽  
Tetragonal Symmetry ◽  
Geometrical Parameters ◽  
Fe Model ◽  
Effective Elastic Properties ◽  
Interpenetrating Phase Composites

3D printable two-phase interpenetrating phase composites (IPCs) are designed by embedding a 3D periodic re-entrant lattice structure (as the reinforcing phase) in a matrix phase. These IPCs display the cubic or tetragonal symmetry. A micromechanical model is developed to evaluate effective elastic properties of the IPCs. Effective Young's moduli, shear moduli and Poisson's ratios (PRs) of each IPC are determined from the effective stiffness and compliance matrices of the composite, which are obtained through a homogenization analysis using a unit cell-based finite element (FE) model incorporating periodic boundary conditions. The FE simulation results are also compared with those based on various analytical bounding techniques in micromechanics, including the Voigt–Reuss, Hashin–Shtrikman, and Tuchinskii bounds. The effective properties of the IPC can be tailored by adjusting five geometrical parameters, including two strut lengths, two re-entrant angles and one strut diameter, and elastic properties of the two constituent materials. The numerical results reveal that IPCs with a negative PR can be generated by using a compliant matrix material and large re-entrant angles. In addition, it is found that the two re-entrant angles can greatly affect other effective elastic properties of the IPC: the effective shear modulus can be enhanced, while the effective Young's modulus can be enhanced or compromised with the increase of the re-entrant angles. Furthermore, it is seen that by adjusting one of the two re-entrant angles or one of the two strut lengths, the material symmetry exhibited by the IPC can be changed from cubic to tetragonal.

scholarly journals Computation of Effective Elastic Properties Using a Three-Dimensional Semi-Analytical Approach for Transversely Isotropic Nanocomposites

2021 ◽  
Vol 11 (4) ◽  
pp. 1867
Author(s):  
Monica Tapia ◽  
Y. Espinosa-Almeyda ◽  
R. Rodríguez-Ramos ◽  
José A. Otero
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Elastic Properties ◽  
Three Dimensional ◽  
Transversely Isotropic ◽  
Geometrical Shape ◽  
Effective Elastic Properties ◽  
Periodic Cell ◽  
Local Problems ◽  
Element Method

A three-dimensional semi-analytical finite element method (SAFEM-3D) is implemented in this work to calculate the effective properties of periodic elastic-reinforced nanocomposites. Different inclusions are also considered, such as discs, ellipsoidals, spheres, carbon nanotubes (CNT) and carbon nanowires (CNW). The nanocomposites are assumed to have isotropic or transversely isotropic inclusions embedded in an isotropic matrix. The SAFEM-3D approach is developed by combining the two-scale asymptotic homogenization method (AHM) and the finite element method (FEM). Statements regarding the homogenized local problems on the periodic cell and analytical expressions of the effective elastic coefficients are provided. Homogenized local problems are transformed into boundary problems over one-eighth of the cell. The FEM is implemented based on the principle of the minimum potential energy. The three-dimensional region (periodic cell) is divided into a finite number of 10-node tetrahedral elements. In addition, the effect of the inclusion’s geometrical shape, volume fraction and length on the effective elastic properties of the composite with aligned or random distributions is studied. Numerical computations are developed and comparisons with other theoretical results are reported. A comparison with experimental values for CNW nanocomposites is also provided, and good agreement is obtained.

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