1.1. Document Overview
This document describes how to create an input file for Sierra/SM. Highlights of the document contents are as follows:
Section 1 presents the overall structure of the input file, including conventions for the command descriptions, style guidelines for file preparation, and naming conventions for input files that reference the ExodusII database [[1]]. The chapter also gives an example of the general structure of an input file that employs the concept of scope.
Section 2 explains some of the commands that are general to various applications based on the SIERRA Framework. These commands define scopes, functions, and coordinate systems, and they let you set up some of the main time control parameters (begin time, end time, time blocks) for your analysis. (Time control and time step control are discussed in more detail in Section 3 and Section 4.) Other capabilities documented in this chapter are available for calculating element distortion and for activating and deactivating functionality at different times throughout an analysis.
Section 3 describes how to set the start time, end time, and time blocks for an explicit dynamic analysis. This chapter also discusses various options for controlling the critical time step for transient dynamics.
Section 4 discusses the multilevel, nonlinear iterative solver used for implicit calculations. This chapter also describes how to set start time, end time, and time blocks for an implicit analysis.
Section 5 describes material models that can be used in conjunction with the elements. Most of the material models can be used for both explicit and implicit analyses. Even though a material model can be used by both cases, it may be that the use of the material model is better suited for one type of analysis. For example, a material model set up to characterize behavior over a long time would be better suited for use in implicit analyses than in explicit analyses. In such cases, this will be noted. Section 5 also discusses the application of temperature to a mesh and the computation of thermal strains (isotropic and anisotropic).
Section 6 lists the available elements and describes the commands used to access the various options for the elements. Most elements can be used for both explicit and implicit analyses. If that is not the case, a note is made to that effect. Section 6 also includes descriptions of the commands for mass property calculations, element death, and mesh rebalancing. “Element-like” capabilities and rigid bodies are also discussed in Section 6.
Section 7 documents how to use kinematic boundary conditions, force boundary conditions, initial conditions, and specialized boundary conditions.
Section 8 discusses how to define interactions of contact surfaces.
Section 9 details the various options for obtaining output.
Section 10 provides an overview of the user subroutine functionality.
Section 11 documents how to perform transfers between procedures.
Appendix A provides a sample input file for an explicit dynamic analysis of 16 lead spheres being crushed together inside a steel box. Appendix B provides a sample input file for an implicit, quasistatic analysis of an eraser being pulled across a surface. These problems both emphasize large deformation and contact.
The index allows you to find information about command blocks and command lines. In general, single-level entries identify the page where the command syntax appears, with discussion following soon thereafter—on the same page or on a subsequent page. Page ranges are not provided in this index. Some entries consist of two or more levels. Such entries are typically based on context, including such information as the command blocks in which a command line appears, the location of the discussion related to a particular command line, and tips on usage. The electronic version of this document contains hyperlinked entries from the page numbers listed in the index to the text in the body of the document.