CH_overview.xml

<!--
  This software was produced by NIST, an agency of the
  U.S. government, and by statute is not subject to copyright in the
  United States.  Recipients of this software assume all
  responsibilities associated with its operation, modification and
  maintenance. However, to facilitate maintenance we ask that before
  distributing modified versions of this software, you first contact
  the authors at oof_manager@nist.gov.
-->

<preface id="Chapter-Overview">
  <title>Overview</title>

  <section id="Introduction">
    <title>Introduction</title>
    <para>
      &oof2; is public domain software created at the <ulink
      url="http://www.nist.gov">National Institute of Standards and
      Technology</ulink> (NIST) to investigate the properties of
      microstructures. The microstructure of a material is the
      (usually) complex ensemble of polycrystalline grains, second
      phases, cracks, pores, and other features occurring on length
      scales large compared to atomic sizes.
    </para>
    <para>
      At the simplest level, &oof2; is designed to answer questions
      like, <quote>I know what this material looks like and what it's
      made of, but I wonder what would happen if I pull on it in
      different ways?</quote>, or <quote>I have a picture of this
      stuff and I know that different parts expand more than others as
      the temperature increases -- I wonder where the stresses are
      greatest?</quote>
    </para>

    <para>
      One approach for investigating microstructural behavior is to
      reduce the representation of a microstructure to a small number
      of physical parameters (such as grain size or porosity) and
      develop a model which depends on them. If this type of
      reductionist approach is predictive, then such models can be
      extremely useful. However, when physical properties depend on
      microstructural details (such as the spatial correlation of
      crystallite orientation, the shapes and dispersion of second
      phases, extremes of statistical distributions, or local
      anisotropies) such data reduction is often difficult or
      pointless.
    </para>

    <para>
      &oof2; takes a non-reductionist, brute force approach, but in a
      user-friendly way. The user starts with a digitized image of the
      microstructure and builds a data structure on top of it. All the
      data plus any that can be inferred by the user is used. Tools
      are provided to allow the user to graphically select features in
      the microstructural image and specify their properties. For
      &oof2;, the microstructure is a data structure composed of image
      and property data.
    </para>

    <para>
      The idea of basing calculations on images is not new. <ulink
      url="http://ciks.cbt.nist.gov/garboczi/">Edward Garboczi</ulink>
      and colleagues at NIST have used this approach to investigate
      behavior of cements and porous media. Researchers at Alcoa have
      developed finite element models of textured materials. The
      purpose of creating &oof2; and distributing it freely is to
      supply a generic tool for calculating microstructure-property
      relations.
    </para>

    <section id="Section-History">
      <title>History</title>
      <para>
	The original <application>OOF</application> project was
	started at NIST in the late 1990's by <ulink
	url="http://dmse.mit.edu/faculty/faculty/ccarter/"
	role="external">Craig Carter</ulink>, <ulink
	url="http://www.ctcms.nist.gov/~fuller/">Ed Fuller</ulink>,
	<ulink url="http://www.ctcms.nist.gov/~roosen/">Andy
	Roosen</ulink>, and <ulink
	url="http://math.nist.gov/~SLanger">Steve Langer</ulink>.  At
	first, &oof1; only solved linear elasticity problems, but
	later acquired the ability to handle thermal diffusion as
	well. &oof1; was actually <emphasis>four</emphasis> separate
	programs, <application>ppm2oof</application>, which converted
	images to finite element meshes for elasticity problems,
	<application>oof</application>, which performed virtual
	experiments on the meshes produced by
	<application>ppm2oof</application>, and versions of
	<application>oof</application> and
	<application>ppm2oof</application> for systems with both
	elasticity and thermal diffusion.
      </para>
      <para>
	Meanwhile, Craig Carter moved to <ulink
	url="http://www.mit.edu" role="external">MIT</ulink>, where
	his students Edwin Garcia and Rajesh Raghavan extended &oof1;
	to electromechanical, electrochemical, and viscoplastic
	systems.  It became clear that &oof1;'s architecture would not
	permit all this physics to coexist happily in one program, and
	that maintaining separate versions for a myriad of physical
	applications was not at all feasible.  Furthermore, &oof1;
	could not easily be extended to higher order finite elements
	or to three dimensions.  This provided the motivation for
	&oof2;.
      </para>
      <para>
	&oof2; is a completely new program, sharing almost no code
	with &oof1;. It provides more flexibility than &oof1; (it
	offers more physics, and users can arbitrarily combine
	physical properties within one material), and is more easily
	expandable (developers and adventurous users can add new types
	of physics without creating a separate program).  &oof2; does
	everything within one program; there is no separation between
	the mesh generation code and the mesh solution code. Finally,
	&oof2; will be the basis for <application>OOF3D</application>,
	which will solve three dimensional microstructures.
      </para>

      <para>
        TODO: List of major new features and the versions they
        appeared in.
      </para>

      <para>
        TODO: Past participants in the project who aren't listed as
        authors.
      </para>

    </section>
  </section>

  <section>
    <title>Disclaimer</title>
    <para>
      The research software described herein ("the software") is
      provided by NIST as a public service. You may use, copy and
      distribute copies of the software in any medium, provided that
      you keep intact this entire notice. You may improve, modify and
      create derivative works of the software or any portion of the
      software, and you may copy and distribute such modifications or
      works. Modified works should carry a notice stating that you
      changed the software and should note the date and nature of any
      such change. Please explicitly acknowledge the National
      Institute of Standards and Technology as the source of the
      software. To facilitate maintenance we ask that before
      distributing modified versions of this software, you first
      contact the authors at <email>oof_manager@nist.gov</email>.
    </para>
    <para>
      The software is expressly provided "AS IS". NIST MAKES NO
      WARRANTY OF ANY KIND, EXPRESS, IMPLIED, IN FACT OR ARISING BY
      OPERATION OF LAW, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
      WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE,
      NON-INFRINGEMENT AND DATA ACCURACY. NIST NEITHER REPRESENTS NOR
      WARRANTS THAT THE OPERATION OF THE SOFTWARE WILL BE
      UNINTERRUPTED OR ERROR-FREE, OR THAT ANY DEFECTS WILL BE
      CORRECTED. NIST DOES NOT WARRANT OR MAKE ANY REPRESENTATIONS
      REGARDING THE USE OF THE SOFTWARE OR THE RESULTS THEREOF,
      INCLUDING BUT NOT LIMITED TO THE CORRECTNESS, ACCURACY,
      RELIABILITY, OR USEFULNESS OF THE SOFTWARE.
    </para>
    <para>
      You are solely responsible for determining the appropriateness
      of using and distributing the software and you assume all risks
      associated with its use, including but not limited to the risks
      and costs of program errors, compliance with applicable laws,
      damage to or loss of data, programs or equipment, and the
      unavailability or interruption of operation. This software is
      not intended to be used in any situation where a failure could
      cause risk of injury or damage to property. The software was
      developed by NIST employees. NIST employee contributions are not
      subject to copyright protection within the United States.
    </para>
    <para>
      Any mention of commercial entities in this manual should not be
      taken as an endorsement.  NIST does not endorse products. 
    </para>
  </section>

  <section id="Section-Manual">
    <title>About This Manual</title>
    <para>
      <xref linkend="Chapter-Starting"/> describes how to acquire,
      install, and start &oof2;.  If you're fortunate enough to have
      &oof2; already installed, you can skip most of this chapter,
      although you may want to read <xref linkend="Section-Learning"/>
      to learn about the on-line tutorials.
    </para>
    <para>
      <xref linkend="Chapter-Concepts"/> discusses the various
      objects (Microstructures, Fields, Meshes,
      <foreignphrase>etc.</foreignphrase>) that &oof2; manipulates.
      It would be a good idea to read this now, although the rest of
      the manual (the on-line version, at least) links back to it
      frequently.
    </para>
    <para>
      The main &oof2; GUI consists of a bunch of Task Pages.  <xref
      linkend="Chapter-Tasks"/> describes each page in detail.  This
      is where you go to learn how to do something specific.
    </para>
    <para>
      The &oof2; Graphics Window is covered in <xref
      linkend="Chapter-Graphics"/>.  It discusses how to control what
      is displayed in the window, and all the operations that require
      graphical interaction (selecting pixels with the mouse, for
      example).
    </para>
    <para>
      <xref linkend="Chapter-Windows"/> discusses the remaining parts
      of the &oof2; GUI.
    </para>
    <para>
      <xref linkend="Chapter-Reference"/> is the &oof2; Reference
      Manual.  All operations in the GUI have a text counterpart.
      These text commands form a hierarchical system of menus.  <xref
      linkend="Chapter-Reference"/> lists and describes all of the
      commands in detail, as well as all of the objects that can be
      used as arguments to those commands.
    </para>
    <para>
      <xref linkend="Chapter-Extending"/> and <xref
      linkend="Chapter-Coding"/> describe how to add new features to
      &oof2;.  <xref linkend="Chapter-Extending"/> discusses the
      mechanics: which files need to be created, where to put them,
      and how to compile them into an &oof2; extension module.  <xref
      linkend="Chapter-Coding"/> discusses the contents of the files.
      It describes the classes and subroutines that need to be written
      and provides examples.
    </para>
    <para>
      This manual was written in <ulink url="http://docbook.org"
      role="external">DocBook</ulink> 4.5 XML, and converted to html
      with <ulink url="https://www.saxonica.com"
      role="external"><application>saxon</application></ulink> 6.5.3.
    </para>
  </section>
</preface>

<!-- Keep this comment at the end of the file
  Local variables:
  sgml-omittag:t
  sgml-shorttag:t 
  sgml-namecase-general:nil
  sgml-minimize-attributes:nil
  sgml-always-quote-attributes:t
  sgml-indent-step:2
  sgml-indent-data:t
  sgml-parent-document:("man_oof2.xml" "book" "chapter")
  sgml-exposed-tags:nil
  sgml-local-ecat-files:nil
  End:
-->