XFEM System Requirements Specification

This template follows INL template TEM-135, "IT System Requirements Specification".

commentnote

This document serves as an addendum to Framework System Requirements Specification and captures information for SRS specific to the XFEM module.

Introduction

System Purpose

The purpose of the MOOSE XFEM module is to allow for mesh-independent discontinuities to be introduced into finite-element models using the extended finite element method. These discontinuities can be due to a variety of phenomena, including fractures and material interfaces, and can be used to represent the boundary of the domain being modeled.

System Scope

The MOOSE XFEM module provides capabilities for representing mesh-independent discontinuities in a finite-element model. This is done using the phantom-node variant of the extended finite element method, which introduces discontinuities by duplicating elements cut by the discontinuity, re-connecting those elements to the mesh in an appropriate way, and modifying the integration rule of these cut elements to reflect the fact that only part of the elements represent physical material.

This module provides all of the capabilities needed to use phantom-node-based XFEM. The core of this capability is the cutting algorithm, known as the element fragment algorithm (EFA). The EFA determines which elements should be deleted and added, and which nodes should be added. The XFEM module provides all the capabilities needed to store and use data about the elements that have been cut, and to modify the integration rules for those cut elements.

The XFEM module also provides capabilities for the user to define how the mesh is cut in a variety of ways, including based on primitive geometric objects, meshes, level set fields, or paths determined by stresses or fracture integrals. For crack propagation based on fracture integrals, the XFEM module can provide the information on crack geometry needed to compute those integrals, which are computed externally to this module.

In addition, the XFEM module contains tools to support the setup of models that use XFEM and outputting relevant data for use in visualizing results.

System Overview

System Context

The XFEM module is command-line driven. Like MOOSE, this is typical for a high-performance software that is designed to run across several nodes of a cluster system. As such, all usage of the software is through any standard terminal program generally available on all supported operating systems. Similarly, for the purpose of interacting through the software, there is only a single user, "the user", which interacts with the software through the command-line. The XFEM module does not maintain any back-end database or interact with any system daemons. It is an executable, which may be launched from the command line and writes out various result files as it runs.

Figure 1: Usage of the XFEM module and other MOOSE-based applications.

System Functions

Since the XFEM module is a command-line driven application, all functionality provided in the software is operated through the use of standard UNIX command line flags and the extendable MOOSE input file. The XFEM module is completely extendable so individual design pages should be consulted for specific behaviors of each user-defined object.

User Characteristics

Like MOOSE, there are three kinds of users working on the XFEM module:

  • XFEM module Developers: These are the core developers of the XFEM module. They are responsible for following and enforcing the software development standards of the module, as well as designing, implementing, and maintaining the software.

  • Developers: A scientist or engineer that uses the XFEM module alongside MOOSE to build their own application. This user will typically have a background in modeling or simulation techniques (and perhaps numerical analysis) but may only have a limited skillset when it comes to code development using the C++ language. This is the primary focus group of the module. In many cases, these developers will be encouraged to contribute module-appropriate code back to the XFEM module, or to MOOSE itself.

  • Analysts: These are users that will run the code and perform analysis on the simulations they perform. These users may interact with developers of the system requesting new features and reporting bugs found and will typically make heavy use of the input file format.

Assumptions and Dependencies

The XFEM module is developed using MOOSE and can itself be based on various MOOSE modules, as such the SRS for the XFEM module is dependent upon the files listed at the beginning of this document. Any further assumptions or dependencies are outlined in the remainder of this section.

The XFEM module has no constraints on hardware and software beyond those of the MOOSE framework and the Solid Mechanics module. The XFEM module provides access to a number of code objects that perform computations. These objects each make their own physics-based assumptions, such as the units of the inputs and outputs. Those assumptions are described in the documentation for those individual objects.

References

  1. ISO/IEC/IEEE 24765:2010(E). Systems and software engineering—Vocabulary. first edition, December 15 2010.[BibTeX]
  2. ASME NQA-1. ASME NQA-1-2008 with the NQA-1a-2009 addenda: Quality Assurance Requirements for Nuclear Facility Applications. first edition, August 31 2009.[BibTeX]

Definitions and Acronyms

This section defines, or provides the definition of, all terms and acronyms required to properly understand this specification.

Definitions

  • Verification: (1) The process of: evaluating a system or component to determine whether the products of a given development phase satisfy the conditions imposed at the start of that phase. (2) Formal proof of program correctness (e.g., requirements, design, implementation reviews, system tests) (24765:2010(E), 2010).

Acronyms

AcronymDescription
INLIdaho National Laboratory
LGPLGNU Lesser General Public License
MOOSEMultiphysics Object Oriented Simulation Environment
NQA-1Nuclear Quality Assurance Level 1
POSIXPortable Operating System Interface
SRSSoftware Requirement Specification

System Requirements

In general, the following is required for MOOSE-based development:

A POSIX compliant Unix-like operating system. This includes any modern Linux-based operating system (e.g., Ubuntu, Fedora, Rocky, etc.), or a Macintosh machine running either of the last two MacOS releases.

HardwareInformation
CPU Architecturex86_64, ARM (Apple Silicon)
Memory8 GB (16 GBs for debug compilation)
Disk Space30GB

LibrariesVersion / Information
GCC9.0.0 - 12.2.1
LLVM/Clang10.0.1 - 19
Intel (ICC/ICX)Not supported at this time
Python3.10 - 3.13
Python Packagespackaging pyaml jinja2

Functional Requirements

  • xfem: Bimaterials
  • 23.1.1The XFEM module shall have the capability to calculate mechanical response in two glued, layered materials with the interface location and material properties applied to on each side of the boundary determined by a level set function.
  • 23.1.2The XFEM module shall have the capability to calculate mechanical response in a composite material matrix with an inclusion with the location of the inclusion boundary and material properties applied to the matrix and inclusion determined by a prescribed level set function.
  • 23.1.3The system shall have the capability to calculate the mechanical response in two glued, layered materials with the interface location and automatic differentiation material properties applied to on each side of the boundary determined by a level set function.
  • 23.1.4The XFEM module shall have the capability to calculate mechanical response in a composite material matrix with an inclusion with the location of the inclusion boundary and material properties applied to the matrix and inclusion determined by a prescribed level set function using automatic differentiation.
  • xfem: Checkpoint
  • 23.2.1The XFEM module shall support outputting of checkpoint files.
  • xfem: Corner Nodes Cut
  • 23.3.1The XFEM module shall have the capability of cutting directly through multiple nodes of a single QUAD4 element in 2D.
  • 23.3.2The XFEM module shall be able to perform mesh cuts on any combination of the edges of elements and through elements including allowing cuts that go through the nodes on the same mesh.
  • 23.3.3The XFEM module shall have the capability of perfoming mesh cuts on the edges of elements such that only two new nodes are generated to separate the previously connected elements.
  • 23.3.4The XFEM module shall be capable of propagating an existing crack front along a prescribed cut in 2D.
  • xfem: Crack Tip Enrichment
  • 23.4.1The XFEM module shall have the capability to include near-tip enrichment functions in 2D mechanics simulations.
  • 23.4.2The XFEM module shall have the capability to include near-tip enrichment functions in 3D mechanics simulations.
  • xfem: Diffusion Xfem
  • 23.5.1The XFEM Module shall have the capability to run 2D diffusion problems with prescribed values on the domain boundary (Dirichlet conditions) with a fixed position discontinuous interface through mesh elements.
  • 23.5.2The XFEM Module shall have the capability to run 2D diffusion problems with prescribed solution values on the domain boundary (Dirichlet conditions) and prescribed boundary flux values (Neumann conditions) with a fixed position discontinuous interface defined by a geometric cut user object.
  • 23.5.3The XFEM Module shall have the capability to run 2D diffusion problems with a fixed position discontinuous interface defined by the location of the zero values of a level set function with the level set variable being a Moose Variable.
  • 23.5.4The XFEM Module shall have the capability to run 2D diffusion problems with a fixed position discontinuous interface defined by the location of the zero values of a prescribed level set function with the level set variable being a Moose AuxVariable.
  • 23.5.5The XFEM Module shall have the capability to run 3D diffusion problems with a fixed position discontinuous interface defined by the location of the zero values of a prescribed level set function with the level set variable being a Moose AuxVariable.
  • xfem: High Order Elements
  • 23.6.1The XFEM module shall permit modeling of discontinuities represented with XFEM with second-order elements in 2D using TRI6 elements.
  • 23.6.2The XFEM module shall permit modeling of discontinuities represented with XFEM with third-order elements in 2D using TRI7 elements.
  • 23.6.3The XFEM module shall permit modeling of discontinuities represented with XFEM with second-order elements in 2D using QUAD8 elements.
  • 23.6.4The XFEM module shall permit modeling of discontinuities represented with XFEM with second-order elements in 2D using QUAD9 elements.
  • 23.6.5The XFEM module shall permit modeling of discontinuities represented with XFEM with second-order elements in 2D using QUAD9 elements when the XFEM cutting plane is prescribed using a level set field.
  • 23.6.6The XFEM module shall permit modeling of discontinuities represented with XFEM with second-order elements in 3D using TET10 elements when the XFEM cutting plane is prescribed using a level set field.
  • 23.6.7The XFEM module shall permit modeling of discontinuities represented with XFEM with third-order elements in 3D using TET14 elements when the XFEM cutting plane is prescribed using a level set field.
  • 23.6.8The XFEM module shall permit modeling of discontinuities represented with XFEM with second-order elements in 3D using HEX20 elements when the XFEM cutting plane is prescribed using a level set field.
  • 23.6.9The XFEM module shall permit modeling of discontinuities represented with XFEM with second-order elements in 3D using HEX27 elements when the XFEM cutting plane is prescribed using a level set field.
  • 23.6.10The XFEM module shall permit modeling of branching of discontinuities represented with XFEM by sequentially cutting second-order elements in 2D using QUAD8 elements.
  • 23.6.11The XFEM module shall permit modeling of branching of discontinuities represented with XFEM by sequentially cutting second-order elements in 2D using QUAD9 elements.
  • 23.6.12The XFEM module shall permit modeling of branching of discontinuities represented with XFEM by sequentially cutting second-order elements in 2D using TRI6 elements.
  • 23.6.13The XFEM module shall permit modeling of branching of discontinuities represented with XFEM by sequentially cutting third-order elements in 2D using TRI7 elements.
  • xfem: Init Solution Propagation
  • 23.7.1The XFEM module shall retain the values of auxiliary variables on child nodes and elements after running the cutting algorithm, and initialize solution variables on newly created nodes with values from parent nodes in parallel
  • xfem: Mechanical Constraint
  • 23.8.1The XFEM module shall permit applying a glued constraint across the XFEM interface for 2D solid mechanics problems.
  • xfem: Mesh Cut 2D Fracture
  • 23.9.1The XFEM module shall represent a propagating crack in a 2D mechanics model with XFEM, where the crack is defined using a topologically defined surface cutting mesh by MeshCut2DFunctionUserObject
    1. and crack growth and direction is computed by a fracture integral with constant fracture toughness.
    2. and crack growth and direction is computed by a fracture integral with fracture toughness sampled from a material at the crack tip.
    3. and crack growth is a maximum stress criterion and the growth direction is in the original crack direction.
    4. and crack growth and direction is computed by a fracture integral with constant fracture toughness or maximum stress criterion.
    5. and produce an error when fracture toughness is specified by more than one input source.
    6. and crack growth is defined by a function. The average crack tip stress changes with crack orientation and properly accounts volume averaging near surfaces.
  • xfem: Moment Fitting
  • 23.10.1The XFEM module shall permit the use of the moment fitting algorithm to compute integration point weights for partial elements on 2D solid mechanics problems
  • 23.10.2The XFEM module shall permit the use of the moment fitting algorithm to compute integration point weights for partial elements on 2D problems with a 4-point integration rule
  • 23.10.3The XFEM module shall permit the use of the moment fitting algorithm to compute integration point weights for partial elements on 2D problems with a 6-point integration rule
  • xfem: Moving Interface
  • 23.11.1The XFEM module shall provide an ability to specify whether an XFEM cut surface should be healed independently for individual interfaces
  • 23.11.2The XFEM module shall not output summary information on mesh changes when debug_output_level=0
  • 23.11.3The XFEM module shall output summary information on mesh changes when debug_output_level=1
  • 23.11.4The XFEM module shall output detailed information on mesh changes when debug_output_level=2
  • 23.11.5The XFEM module shall output detailed information on mesh changes when debug_output_level=3
  • 23.11.6The XFEM module shall provide an ability to solve bi-material mechanics problems where a moving material interface is defined by an XFEM surface, which is defined by a prescribed level set field.
  • 23.11.7The XFEM module shall provide an ability to solve bi-material mechanics problems where a moving material interface is defined by an XFEM surface, which is defined by a prescribed level set field, while using the automatic differentiation capability.
  • 23.11.8The XFEM module shall provide an ability to solve bi-material mechanics problems at finite strain where a moving material interface is defined by an XFEM surface, which is defined by a prescribed level set field.
  • 23.11.9The XFEM module shall provide an ability to modify subdomain IDs based on an XFEM interface.
  • 23.11.10The XFEM module shall provide an ability to solve bi-material diffusion problems where a moving material interface is defined by an XFEM surface, which is defined by a prescribed level set field.
  • 23.11.11The XFEM module shall provide an ability to solve bi-material diffusion problems where a moving material interface is defined by an XFEM surface, which is defined by a prescribed level set field, while using automatic differentiation.
  • 23.11.12The XFEM module shall provide an ability to solve a simple 2d phase transition problem in which the phase boundary is defined by and XFEM surface and the interface velocity depends on the jump of variables and gradients across the interface.
  • 23.11.13The XFEM module shall provide an ability to solve a simple 3d phase transition problem in which the phase boundary is defined by and XFEM surface and the interface velocity depends on the jump of variables and gradients across the interface.
  • 23.11.14The XFEM module shall provide an ability to solve a 2d simple phase transition problem in which the phase boundary is defined by and XFEM surface and the interface velocity depends on the jump of variables and gradients across the interface using the automatic differentiation capability.
  • 23.11.15The XFEM module shall provide an ability to cut one block with a moving circle surface mesh in 2D.
  • 23.11.16The XFEM module shall provide an ability to cut one block with a moving cylinder surface mesh in 3D.
  • 23.11.17The XFEM module shall accurately solve 1D, xy problems with homogeneous material properties with a moving interface determined by a user prescribed level set function, and problem results are verified using the Method of Manufactured Solutions.
  • 23.11.18The XFEM module shall accurately solve 1D, xy problems with material properties and a moving interface dependent on a user prescribed level set function, and problem results are verified using the Method of Manufactured Solutions.
  • 23.11.19The XFEM module shall accurately solve 1D, xy problems with a moving interface separating two discrete materials prescribed by a user defined level set function with problem results verified using the Method of Manufactured Solutions.
  • 23.11.20The XFEM module shall accurately solve 1D, rz problems with homogeneous material properties with a moving interface determined by a user prescribed level set function, and problem results are verified using the Method of Manufactured Solutions.
  • 23.11.21The XFEM module shall accurately solve 1D, rz problems with material properties and a moving interface dependent on a user prescribed level set function, and problem results are verified using the Method of Manufactured Solutions.
  • 23.11.22The XFEM module shall accurately solve 2D, xy problems with homogeneous material properties with a moving interface determined by a user prescribed level set function, and problem results are verified using the Method of Manufactured Solutions.
  • 23.11.23The XFEM module shall accurately solve 2D, xy problems with material properties and a moving interface dependent on a user prescribed level set function, and problem results are verified using the Method of Manufactured Solutions.
  • 23.11.24The XFEM module shall accurately solve 2D, rz problems with homogeneous material properties with a moving interface determined by a user prescribed level set function, and problem results are verified using the Method of Manufactured Solutions.
  • 23.11.25The XFEM module shall accurately solve 2D, rz problems with material properties and a moving interface dependent on a user prescribed level set function, and problem results are verified using the Method of Manufactured Solutions.
  • xfem: Nucleation Uo
  • 23.12.1The system shall nucleate and grow edge and bulk cracks based on a nucleation threshold given by an auxvariable.
  • 23.12.2The system shall not nucleate edge cracks within a nucleation_radius of other cracks.
  • 23.12.3The system shall nucleate bulk and edge cracks that cut a single element if no nucleation length is given.
  • 23.12.4The system shall error if the nucleation length is smaller than the element being cut.
  • 23.12.5The system shall suppress the error if the nucleation length is smaller than the element being cut and nucleate a cut across the single element.
  • xfem: Pressure Bc
  • 23.13.1The XFEM module shall permit application of pressure boundary conditions to XFEM cut surfaces in 2D
  • 23.13.2The XFEM module shall permit application of pressure boundary conditions to XFEM cut surfaces in 3D
  • 23.13.3The XFEM module shall permit application of pressure boundary conditions to inclined XFEM cut surfaces in 2D
  • 23.13.4The XFEM module shall permit application of pressure boundary conditions to XFEM cut surfaces in 2D finite deformation simulations
  • xfem: Side Integral
  • 23.14.1The XFEM module shall properly integrate quantities on sides of cut elements that are intersected by the cutting plane in 2D
  • 23.14.2The XFEM module shall properly integrate quantities on sides of cut elements that are intersected by the cutting plane in 3D
  • xfem: Single Var Constraint 2D
  • 23.15.1The XFEM module shall provide an ability to apply a zero-jump, zero-flux-jump constraint across a propagating XFEM interface for one variable.
  • 23.15.2The XFEM module shall provide an ability to apply a zero-jump, zero-flux-jump constraint across a propagating XFEM interface for one variable in a problem with another variable that does not have a constraint across that interface.
  • 23.15.3The XFEM module shall provide an ability to apply zero-jump, zero-flux-jump constraints across a propagating XFEM interface for two variables.
  • 23.15.4The XFEM module shall provide an ability to apply a zero-jump, zero-flux-jump constraint on a stationary interface for one variable.
  • 23.15.5The XFEM module shall provide an ability to apply a zero-jump, nonzero-flux-jump (defined by a Real value) constraint on a stationary interface for one variable.
  • 23.15.6The XFEM module shall provide an ability to apply a zero-jump, nonzero-flux-jump (defined by a function) constraint on a stationary interface for one variable.
  • 23.15.7The XFEM module shall provide an ability to apply a nonzero-jump (defined by a Real value), zero-flux-jump constraint on a stationary interface for one variable.
  • 23.15.8The XFEM module shall provide an ability to apply a nonzero-jump (defined by a function), zero-flux-jump constraint on a stationary interface for one variable.
  • 23.15.9The XFEM module shall provide an ability to apply a nonzero-jump, nonzero-flux-jump constraint on a stationary interface for one variable.
  • 23.15.10The XFEM module shall provide an ability to apply a two-sided equal value constraint on a stationary interface for one variable.
  • xfem: Single Var Constraint 3D
  • 23.16.1The XFEM module shall provide an ability to apply a zero-jump, zero-flux-jump constraint across a stationary XFEM interface for one variable in 3D.
  • 23.16.2The XFEM module shall provide an ability to apply a zero-jump, nonzero-flux-jump constraint across a stationary XFEM interface for one variable in 3D.
  • 23.16.3The XFEM module shall provide an ability to apply a nonzero-jump, zero-flux-jump constraint across a stationary XFEM interface for one variable in 3D.
  • 23.16.4The XFEM module shall provide an ability to apply a nonzero-jump, nonzero-flux-jump constraint across a stationary XFEM interface for one variable in 3D.
  • xfem: Solid Mechanics Basic
  • 23.17.1The XFEM module shall represent a propagating crack in a 2D mechanics problem in which crack growth occurs when the average stress in the element at the crack tip exceeds a critical value.
  • 23.17.2The XFEM module shall represent a propagating crack in a 2D mechanics problem in which crack growth occurs when the average stress in the element at the crack tip exceeds a critical value defined by the value of a field variable.
  • 23.17.3The XFEM module shall represent a propagating crack in a 2D mechanics problem in which crack growth occurs when the stress at any of the quadrature points in the element at the crack tip exceeds a critical value defined by the value of a field variable.
  • 23.17.4The XFEM module shall permit definition of a stationary crack in a 3D mechanics model with XFEM, where the crack is defined using a rectangular cutting plane by RectangleCutUserObject
  • 23.17.5The XFEM module shall represent a propagating crack in a 3D mechanics model with XFEM, where the crack is defined using a topological surface cutting mesh by CrackMeshCut3DUserObject and allowed to propagate with
    1. growth speeds determined by the fatigue cracking Paris law, or
    2. growth directions determined by computing the maximum hoop stress law using interaction integrals, or
    3. growth directions determined by an parsed function.
  • 23.17.6The XFEM system shall permit computation of fracture domain integrals in 3D mechanics problems where a stationary embedded circular crack is defined by a cutting plane geometry and points along the crack front for the the domain integral
    1. explicitly specified.
    2. are provided by a class that derives from CrackFrontPointsProvider.
  • 23.17.7The XFEM module shall permit definition of a stationary crack in a 3D mechanics model with XFEM, where the crack is defined using an elliptical cutting plane by EllipseCutUserObject
  • 23.17.8The XFEM system shall permit branched cracks to be represented in 2D by sequentially cutting a 4-noded quadrilateral element by two prescribed evolving cutting planes
  • 23.17.9The XFEM system shall permit branched cracks to be represented in 2D by sequentially cutting a 3-noded triangle element by two prescribed evolving cutting planes
  • 23.17.10The XFEM system shall provide an accessor function to the crack_tip_origin_direction_map
  • xfem: Switching Material
  • 23.18.1The XFEM module shall provide an ability to switch materials for one stationary cut.
  • 23.18.2The XFEM module shall provide an ability to switch materials for one moving cut.
  • 23.18.3The XFEM module shall allow switching materials based on the side of an interface for a single moving cut defined using a mesh as the cutting object.
  • 23.18.4The XFEM module shall provide an ability to switch materials for two stationary cuts.
  • 23.18.5The XFEM module shall provide an ability to switch materials for two moving cuts.

Usability Requirements

No requirements of this type exist for this application, beyond those of its dependencies.

Performance Requirements

No requirements of this type exist for this application, beyond those of its dependencies.

System Interfaces

No requirements of this type exist for this application, beyond those of its dependencies.

System Operations

Human System Integration Requirements

The XFEM module is command line driven and conforms to all standard terminal behaviors. Specific human system interaction accommodations shall be a function of the end-user's terminal. MOOSE (and therefore the XFEM module) does support optional coloring within the terminal's ability to display color, which may be disabled.

Maintainability

  • The latest working version (defined as the version that passes all tests in the current regression test suite) shall be publicly available at all times through the repository host provider.

  • Flaws identified in the system shall be reported and tracked in a ticket or issue based system. The technical lead will determine the severity and priority of all reported issues and assign resources at their discretion to resolve identified issues.

  • The software maintainers will entertain all proposed changes to the system in a timely manner (within two business days).

  • The core software in its entirety will be made available under the terms of a designated software license. These license terms are outlined in the LICENSE file alongside the XFEM module source code. As a MOOSE physics module, the license for the XFEM module is identical to that of the framework - that is, the LGPL version 2.1 license.

Reliability

The regression test suite will cover at least 80% of all lines of code within the XFEM module at all times. Known regressions will be recorded and tracked (see Maintainability) to an independent and satisfactory resolution.

System Modes and States

MOOSE applications normally run in normal execution mode when an input file is supplied. However, there are a few other modes that can be triggered with various command line flags as indicated here:

Command Line FlagDescription of mode
-i <input_file>Normal execution mode
--split-mesh <splits>Read the mesh block splitting the mesh into two or more pieces for use in a subsequent run
--use-split(implies -i flag) Execute the simulation but use pre-split mesh files instead of the mesh from the input file
--yamlOutput all object descriptions and available parameters in YAML format
--jsonOutput all object descriptions and available parameters in JSON format
--syntaxOutput all registered syntax
--registryOutput all known objects and actions
--registry-hitOutput all known objects and actions in HIT format
--mesh-only (implies -i flag)Run only the mesh related tasks and output the final mesh that would be used for the simulation
--start-in-debugger <debugger>Start the simulation attached to the supplied debugger
commentnote

The list of system-modes may not be extensive as the system is designed to be extendable to end-user applications. The complete list of command line options for applications can be obtained by running the executable with zero arguments. See the command line usage.

Physical Characteristics

The XFEM module is software only with no associated physical media. See System Requirements for a description of the minimum required hardware necessary for running the XFEM module.

Environmental Conditions

Not Applicable

System Security

MOOSE-based applications such as the XFEM module have no requirements or special needs related to system security. The software is designed to run completely in user-space with no elevated privileges required nor recommended.

Information Management

The core framework and all modules in their entirety will be made publicly available on an appropriate repository hosting site. Day-to-day backups and security services will be provided by the hosting service. More information about MOOSE backups of the public repository on INL-hosted services can be found on the following page: GitHub Backups

Polices and Regulations

MOOSE-based applications must comply with all export control restrictions.

System Life Cycle Sustainment

MOOSE-based development follows various agile methods. The system is continuously built and deployed in a piecemeal fashion since objects within the system are more or less independent. Every new object requires a test, which in turn requires an associated requirement and design description. The XFEM module development team follows the NQA-1 standards.

Packaging, Handling, Shipping and Transportation

No special requirements are needed for packaging or shipping any media containing MOOSE and XFEM module source code. However, some MOOSE-based applications that use the XFEM module may be export-controlled, in which case all export control restrictions must be adhered to when packaging and shipping media.

Verification

The regression test suite will employ several verification tests using comparison against known analytical solutions, the method of manufactured solutions, and convergence rate analysis.