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Attribute
A database attribute is an entity within the database, defining a specific property of a material. Attributes may be material properties such as Youngs Modulus or database organizational entities such as Date Last Modified. Attributes may be numbers, character strings or curves. Attributes are organized into logical groups called
Relations, 8.
Column Headers
When the database is displayed in the Materials Selector form, several database attributes or attribute expressions are presented at the top of the spreadsheet columns. These attributes or expressions are the column headers.
There are two types of column headers: pedigree and property set.
The
Pedigree, 7 column headers are used to select materials from the database. Each row in the spreadsheet represents a unique combination of the pedigree column headers.
The
Property Set, 7 column headers display the range of values for the row’s pedigree column headers. If there are no pedigree column headers, then only a single material row appears displaying the entire range of values for the column headers.
The column headers are saved as part of the template.
Databank
A database provided by MSC.Software, such as the Standard Databanks of U.S. Government data or the Producers Databanks.
Database
A database is an MSC Mvision materials database file.The Patran Materials reads MSC Mvision databases and stores selected material properties in the Patran database.
Expressions
Expressions are any mathematical calculation consisting of
MSC Mvision attributes, values,
Functions, 5, and operators. For example,
777.777
temp
temp/777.777
log( temp )
log( temp ) * e11t/e22t
interp_x( cpvstemp, 72 )
sqrt( log( sin( temp )))
where temp and ctcvstemp are database attributes. These expressions are used in queries, mappings, and column headers.
Figures
Figures are MSC Mvision attributes that are composed of graphical elements. A graphical element is either curve points, scatter points and/or runout points. The Patran Materials uses only the curve points and displays these as solid lines.
Functions
These are the available functions for
Expressions, 4 in the queries, mappings and column headers.
Function | Description | Example |
abs | Absolute value | abs( -2.7 ) = 2.7, abs( 2.7) = 2.7 |
acos | Arc cosine | acos( .5 ) (Radians) |
asin | Arc sine | asin ( .5 ) (Radians) |
atan | Arc tangent | atan( .5 ) (Radians) |
ceil | Smallest integer not less than x | ceil( -2.7) = -2, ceil( 2.7 ) = 3 |
cos | Cosine | cos( .5 ) (Radians) |
cosh | Hyperbolic cosine | cosh( .5 ) (Radians) |
degtorad | Degrees to radians | degtorad( 180 ) = 3.14159 |
erf | Error function | erf( .5 ) |
exp | e raised to the power of x | exp( 1 ) = 2.71828 |
floor | Greatest integer not greater than x | ceil( -2.7) = -3, ceil( 2.7 ) = 2 |
if | Conditional statement. Returns the value of first expression if logical expression is true; otherwise, returns the second | if (logical expression, any expression, any expression) if ( e11t ex, e11t, 777 ) Note: “any expression” must be of the same types, reals with reals, curves with curves, etc... |
interp_x | Interpolate on x axis | interp_x( cpvstemp, 100 ) |
interp_y | Interpolate on y axis | interp_y( cpvstemp, 100 ) |
log | Natural log | log( 2.71828 ) = 1 |
log10 | Log base 10 | log( 100 ) = 2 |
nvl | Conditional Null, 7 statement. Returns the first expression if its non-null; otherwise, returns the second. | nvl( any expression, any expression ) nvl( interp_x( cpvstemp, temp ), cp ) Use cp’s value if interp_x(cpvstemp, temp ) is null Note: “any expression” must be of the same types, reals with reals, curves with curves, etc... |
radtodeg | Radians to degrees | radtodeg( 3.14159 ) = 180 |
round | Round to nearest integer | round( -2.7 ) = -3, round( 2.7 ) = 3 |
sin | Sine | sin( .5 ) (Radians) |
sinh | Hyperbolic sine | sinh( .5 ) (Radians) |
sqrt | Square root | sqrt( 16 ) = 4 |
tan | Tangent | tan( .5 ) (Radians) |
tanh | Hyperbolic tangent | tanh( .5 ) (Radians) |
trunc | Truncate real to integer | trunc( -2.7 ) = -2, trunc( 2.7) = 2 |
Mapping
Mapping is the assignment of MSC Mvision database attributes to Patran material properties. Attributes differ from database to database, especially for custom databases created with the MSC Mvision System Builder. Mapping is required to make the transfer of data from the MSC Mvision database to Patran. The mapping is saved as part of the template.
Null
Null is MSC Mvision representation of not having any data for an attribute at a given condition. It is represented on the display as “-0-”.
Pedigree
Pedigree attributes are attributes which define a material. These are attributes which describe its name, type, form, etc... All other attributes provide properties of the material such as its elastic modulus, specific heat, stress/strain curve, etc.
Property Set
Materials databases are divided into several tables. There is at least one pedigree table and at least one property set table. The pedigree tables contain the attributes which define the material (e.g., name, type, form, etc...) The property set tables contain attributes which define properties (e.g., elastic modulus, specific heat, stress/strain curve, etc...) The common material properties are grouped into property set tables so they can be worked with easily. Typically, linear data is grouped into a property set and each curve is grouped into its own property set. So, if a material had both linear and nonlinear data, they would be represented in separate property sets.
Query
The query is a set of conditions placed upon the database, limiting the materials shown in the Materials Selector. A typical query might be to display the materials with a Tensile Modulus of Elasticity greater than 10 Msi (E_T > 10). A Query Panel is available to assist in the creation of valid query commands. The Query Panel lists the databank attributes and pertinent information such as attribute units. The query conditions are stored in the template.
Relations
A database relation is a collection of attributes forming a table, a figure, or a level in the database hierarchy. These relations determine how their attributes display in the material displays. In the Material Select Panel,
pedigree attributes display as single values and property attributes display as ranges. In
Property Set, 7 select panel, all attributes display as single values.
In this example, cname and temp are pedigree attributes and table and e11t are
Property Set, 7 attributes.
Template
A template is a special file associated with a MSC Mvision database that determines how the user sees an MSC Mvision database. The template saves the mapping of database attributes to Patran properties, the column headers, and query conditions. Each database has multiple templates, one for each of the Patran material types (Isotropic, Orthotropic, etc.). The appropriate template is applied automatically when a database is opened.
Uniquing
Uniquing is the process of selecting a unique material from the Materials Selector. The material display allows a material type to be picked. But it is very likely that the material chosen has several subtypes. So it is necessary to complete the selection by picking the material from all possible differences. The Property Set Panel displays all the possible choices that the selected property set can have. This panel displays only those property sets which have attributes mapped and only those attributes which have differences. For a complete listing of the attribute values, change the
Material Application Selection Display, 28 option from “Mapped Properties” to “Database Attributes.” All non-null attributes with values display here.
