An Integrated Approach for Statistical Microscale Homogenization to Macroscopic Dynamic Fracture Analysis

2018 ◽  
Author(s):  
Bahador Bahmani ◽  
Ming Yang ◽  
Anand Nagarajan ◽  
Philip L. Clarke ◽  
Soheil Soghrati ◽  
...  
Keyword(s):  
Finite Element ◽  
Adaptive Mesh Refinement ◽  
Adaptive Mesh ◽  
Integrated Approach ◽  
Fracture Analysis ◽  
Uniaxial Tensile ◽  
Material Interfaces ◽  
Element Mesh ◽  
Structured Adaptive Mesh Refinement ◽  
Fracture Simulation

Maintaining material inhomogeneity and sample-to-sample variations is crucial in fracture analysis, particularly for quasibrittle materials. We use statistical volume elements (SVEs) to homogenize elastic and fracture properties of ZrB2-SiC, a two-phase composite often used for thermal coating. At the mesoscale, a 2D finite element mesh is generated from the microstructure using the Conforming to Interface Structured Adaptive Mesh Refinement (CISAMR), which is a non-iterative algorithm that tracks material interfaces and yields high-quality conforming meshes with adaptive operations. Analyzing the finite element results of the SVEs under three traction loadings, elastic and angle-dependent fracture strengths of SVEs are derived. The results demonstrate the statistical variation and the size effect behavior for elastic bulk modulus and fracture strengths. The homogenized fields are mapped to macroscopic material property fields that are used for fracture simulation of the reconstructed domain under a uniaxial tensile loading by the asynchronous Spacetime Discontinuous Galerkin (aSDG) method.

scholarly journals Reliable Computation of Contact Force in FRP Composite Laminates under Transverse Impact

2004 ◽  
Vol 11 (2) ◽  
pp. 129-142 ◽  
Author(s):  
B.B. Mahanta ◽  
P. Reddy ◽  
Anjan Dutta ◽  
Debabrata Chakraborty
Keyword(s):  
Finite Element ◽  
Contact Force ◽  
Composite Laminates ◽  
Adaptive Mesh Refinement ◽  
Adaptive Mesh ◽  
Contact Period ◽  
Transverse Impact ◽  
Element Analysis ◽  
Element Mesh ◽  
Frp Composite

A simple and computationally efficient adaptive finite element analysis strategy has been adopted for accurate and reliable evaluation of contact force under transverse impact. Contact of a spherical and cylindrical impactor on FRP composite laminates are considered. Adaptive mesh refinement enables the finite element mesh to be obtained iteratively and automatically for the solution to have the desired level of accuracy. The refined meshes influence the calculated contact force and contact period appreciably. Influences of impactor velocity, mass of impactor, mass of the plate on discretization error as well as on contact force history have also been studied and are found to be sensitive.

scholarly journals AMReX: Block-structured adaptive mesh refinement for multiphysics applications

2021 ◽  
pp. 109434202110228
Author(s):  
Weiqun Zhang ◽  
Andrew Myers ◽  
Kevin Gott ◽  
Ann Almgren ◽  
John Bell
Keyword(s):  
Adaptive Mesh Refinement ◽  
Mesh Refinement ◽  
Computational Cost ◽  
Adaptive Mesh ◽  
Uniform Mesh ◽  
Physical Processes ◽  
Structured Adaptive Mesh Refinement ◽  
Core Elements ◽  
Accelerator Design ◽  
Block Structured

Block-structured adaptive mesh refinement (AMR) provides the basis for the temporal and spatial discretization strategy for a number of Exascale Computing Project applications in the areas of accelerator design, additive manufacturing, astrophysics, combustion, cosmology, multiphase flow, and wind plant modeling. AMReX is a software framework that provides a unified infrastructure with the functionality needed for these and other AMR applications to be able to effectively and efficiently utilize machines from laptops to exascale architectures. AMR reduces the computational cost and memory footprint compared to a uniform mesh while preserving accurate descriptions of different physical processes in complex multiphysics algorithms. AMReX supports algorithms that solve systems of partial differential equations in simple or complex geometries and those that use particles and/or particle–mesh operations to represent component physical processes. In this article, we will discuss the core elements of the AMReX framework such as data containers and iterators as well as several specialized operations to meet the needs of the application projects. In addition, we will highlight the strategy that the AMReX team is pursuing to achieve highly performant code across a range of accelerator-based architectures for a variety of different applications.

3-Dimensional Hybrid Continuum-Atomistic Simulations for Multiscale Hydrodynamics

2003 ◽  
Author(s):  
H. S. Wijesinghe ◽  
R. Hornung ◽  
A. L. Garcia ◽  
N. G. Hadjiconstantinou
Keyword(s):  
Adaptive Mesh Refinement ◽  
Hybrid Methods ◽  
Lawrence Livermore National Laboratory ◽  
National Laboratory ◽  
Mesh Refinement ◽  
Adaptive Mesh ◽  
Scale Model ◽  
Structured Adaptive Mesh Refinement ◽  
Flow Gradients ◽  
The Continuum

We present an adaptive mesh and algorithmic refinement (AMAR) scheme for modeling multi-scale hydrodynamics. The AMAR approach extends standard conservative adaptive mesh refinement (AMR) algorithms by providing a robust flux-based method for coupling an atomistic fluid representation to a continuum model. The atomistic model is applied locally in regions where the continuum description is invalid or inaccurate, such as near strong flow gradients and at fluid interfaces, or when the continuum grid is refined to the molecular scale. The need for such “hybrid” methods arises from the fact that hydrodynamics modeled by continuum representations are often under-resolved or inaccurate while solutions generated using molecular resolution globally are not feasible. In the implementation described herein, Direct Simulation Monte Carlo (DSMC) provides an atomistic description of the flow and the compressible two-fluid Euler equations serve as our continuum-scale model. The AMR methodology provides local grid refinement while the algorithm refinement feature allows the transition to DSMC where needed. The continuum and atomistic representations are coupled by matching fluxes at the continuum-atomistic interfaces and by proper averaging and interpolation of data between scales. Our AMAR application code is implemented in C++ and is built upon the SAMRAI (Structured Adaptive Mesh Refinement Application Infrastructure) framework developed at Lawrence Livermore National Laboratory. SAMRAI provides the parallel adaptive gridding algorithm and enables the coupling between the continuum and atomistic methods.

scholarly journals Dynamic Load Balancing of Samr Applications on Distributed Systems

2002 ◽  
Vol 10 (4) ◽  
pp. 319-328 ◽  
Author(s):  
Zhiling Lan ◽  
Valerie E. Taylor ◽  
Greg Bryan
Keyword(s):  
Distributed Systems ◽  
Load Balancing ◽  
Dynamic Load ◽  
Adaptive Mesh Refinement ◽  
Heuristic Method ◽  
Adaptive Mesh ◽  
Dynamic Load Balancing ◽  
Dynamic Features ◽  
Structured Adaptive Mesh Refinement ◽  
Two Phases

Dynamic load balancing(DLB) for parallel systems has been studied extensively; however, DLB for distributed systems is relatively new. To efficiently utilize computing resources provided by distributed systems, an underlying DLB scheme must address both heterogeneous and dynamic features of distributed systems. In this paper, we propose a DLB scheme for Structured Adaptive Mesh Refinement(SAMR) applications on distributed systems. While the proposed scheme can take into consideration (1) the heterogeneity of processors and (2) the heterogeneity and dynamic load of the networks, the focus of this paper is on the latter. The load-balancing processes are divided into two phases: global load balancing and local load balancing. We also provide a heuristic method to evaluate the computational gain and redistribution cost for global redistribution. Experiments show that by using our distributed DLB scheme, the execution time can be reduced by 9%- to using parallel DLB scheme which does not consider the heterogeneous and dynamic features of distributed systems.

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