XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX''"> Basic Concepts and Definitions
This section provides several topics that are intended to help you set up your analysis project, and also to choose carefully the most appropriate options when building an analysis model.
Analysis Codes
You will choose an analysis code based on the objective of your analysis, as well as the software available within your company or development group and the standards within that group. You may be required to use proprietary analysis codes developed within your company, or you may choose from a variety of available programs.
The following general-focus MSC analysis codes are used frequently with Patran.
• MSC Nastran provides advanced general purpose analysis and optimization capabilities, for both linear and nonlinear structural and thermal analyses. MSC Nastran provides a broad range of solution types for analyzing stress, vibration, dynamic, nonlinear, acoustic, aeroelasticity, and heat transfer characteristics of structures and mechanical components.
• MSC.Marc provides advanced capabilities for nonlinear analysis. This analysis code provides solutions for structural, thermal and thermal-mechanically coupled problems that include nonlinearities from many sources and advanced material properties.
Application Preferences
Application Preferences are MSC-supplied interfaces to some of the more popular analysis codes. These interfaces convert the data in the Patran database into the required analysis code input decks. Consult your MSC representative for the latest interfaces available for Patran.
Solution Types
In creating your model database at the beginning of the preprocessing stage, you have already selected an analysis code and type, such as MSC Nastran Structural analysis. As part of the Analysis application, you will select a solution type and determine what environmental requirements you can meet by setting solution parameters correctly.
Solution Types are the different solver code modules offered as part of a particular analysis code and type. For example, if you select the MSC Nastran code and structural analysis type, you may choose from the following solution types:
MSC Nastran Structural Solution Types |
Linear Static | Complex Eigenvalue |
Nonlinear Static | Frequency Response |
Normal Modes | Transient Response |
Buckling | Nonlinear Transient |
Implicit Nonlinear | Explicit Nonlinear |
Different solution types assume different models of behavior and often are used with particular types of load and boundary conditions. Each solution type uses a unique set of equations to solve for
analysis results.
Desired Results
A very important part of setting up the analysis with the Analysis application is to define what results data you need back from the analysis code. The results requested include displacements, stresses, strains, and so on. These results will eventually go through postprocessing and be displayed in graphs, plots
and reports.
Many of the analysis codes provide some kind of Output Request subform on which to request particular types of results. Within MSC Nastran, for example, there are Basic and Advanced Output Request forms. The Basic form is shown as an example later in the chapter. It retains the simplicity of allowing you to specify output requests over the entire model. A default set of output requests is always preselected