Flexcom > Data Inputs > $LOAD CASE

Purpose

To customise the contents of the database output files.

Theory

Refer to Database Files for further information on this feature.

Keyword Format

Optional line specifying the set of elements which is be included in the database contents (defaults to SET=ALL if omitted).

[SET=Set Name]

Optional line specifying that statistics are to be included in the database:

[OPTION=STATISTICS] [, START=Statistics Start Time]

Optional line specifying parameters to be included in the database contents. Each of the parameters is denoted by a number as outlined below:

[INCLUDE=List of Numbers]

Optional line specifying parameters to be excluded from the database contents. Each of the parameters is denoted by a number as outlined below:

[EXCLUDE=List of Numbers]

Note that INCLUDE= and EXCLUDE= are mutually exclusive – any given parameter should not appear under both headings.

Optional line specifying whether output relates to nodes or local integration points:

[OUTPUT=Output Location][, NUMBER=Data Storage Points]

Output Location can be NODES (default) or INTEGRATION-POINTS. The significance of the Local Node Input used during postprocessing depends on whether element based outputs are stored on a node or integration point basis. Data Storage Points can have a value of 1 (element mid-points only), 2 (element start and end-points) or 3 (element start, middle and end-points - the default), and is only relevant when Output Location is set to NODES.

This keyword may occur once only in the $LOAD CASE section. It is not relevant for frequency domain dynamic analysis.

The parameters which correspond to the List of Numbers are as follows:

1.Motion

2.Velocity

3.Acceleration

4.Reactions

5.Axial Force

6.Local-y Shear Force

7.Local-z Shear Force

8.Torque

9.Local-y Bending Moment

10.Local-z Bending Moment

11.Effective Tension

12.Local-y Curvature

13.Local-z Curvature

14.Axial Strain

15.Temperature

16.Pressure

17. Damper Power

18. Plastic Strains

19. Equivalent Plastic Strains

20. Vessel Velocities and Accelerations

21. Convected Coordinate Axes

Table Input

Input:	Description
Set Name:	The name of the element set to be included in the database. This defaults to the set ‘All’.
Statistics:	This option allows you to specify whether runtime generated statistics of nodal motions and element restoring forces are included in the database files. Runtime statistics are excluded by default. See Note (b).
Statistics Start Time:	The time (in seconds) from which Flexcom begins calculating runtime statistics. By default, calculation of runtime statistics begins at the end of the analysis ramp time, or at the start of the analysis if no ramp is specified. This entry is ignored unless statistics output to the database is requested. See Note (b).
Motion (1):	This option allows you to specify whether or not nodal motions are included in the motion database file. Nodal motions are included by default.
Velocity (2):	This option allows you to specify whether or not nodal velocities are included in the motion database file. Nodal velocities are excluded by default.
Acceleration (3):	This option allows you to specify whether or not nodal accelerations are included in the motion database file. Nodal accelerations are excluded by default.
Reactions (4):	This option allows you to specify whether reactions at restrained nodes are included in the force database file. Reactions are included by default.
Axial Force (5):	This option allows you to specify whether axial forces are included in the force database file. Axial forces are included by default.
Local-y Shear Force (6):	This option allows you to specify whether shear forces in the local-y axis are included in the force database file. Local-y shear forces are included by default.
Local-z Shear Force (7):	This option allows you to specify whether shear forces in the local-z axis are included in the force database file. Local-z shear forces are included by default
Torque (8):	This option allows you to specify whether torque forces are included in the force database file. Torque forces are excluded by default.
Local-y Bending Moment (9):	This option allows you to specify whether bending moments in the local-y axis are included in the force database file. Local-y bending moments are included by default.
Local-z Bending Moment (10):	This option allows you to specify whether bending moments in the local-z axis are included in the force database file. Local-z bending moments are included by default.
Effective Tension (11):	This option allows you to specify whether effective tensions are included in the force database file. Effective tensions are included by default.
Local-y Curvature (12):	This option allows you to specify whether curvatures in the local-y axis are included in the force database file. Local-y curvatures are included by default.
Local-z Curvature (13):	This option allows you to specify whether curvatures in the local-z axis are included in the force database file. Local-z curvatures are included by default.
Axial Strain (14):	This option allows you to specify whether axial strains are included in the force database file. Axial strains are included by default.
Temperature (15):	This option allows you to specify whether temperatures are included in the force database file. Temperatures are excluded by default.
Pressure (16):	This option allows you to specify whether internal and external pressures are included in the force database file. Internal and external pressures are included by default.
Damper Power (17):	This option allows you to specify whether power generated by damper elements are included in the force database file. Damper powers are excluded by default.
Plastic Strains (18):	This option allows you to specify whether if plastic axial strain, plastic local-y curvature and plastic local-z curvature are included in the force database file. These parameters are excluded by default. See Note (d).
Equivalent Plastic Strains (19):	This option allows you to specify whether if equivalent plastic axial strain and equivalent plastic curvature are included in the force database file. These parameters are excluded by default. See Note (d).
Vessel Velocity and Acceleration (20):	This option allows you to specify whether or not vessel velocities and accelerations are included in the motion database file. Vessel velocities and accelerations are excluded by default.
Convected Coordinate Axes (21):	This option allows you to specify whether or not element convected axes are included in the motion database file (they are excluded by default). These can be very useful for visualisation purposes in the Model View post-simulation. See Note (g).
Output Location:	This option allows you to specify whether element based outputs are provided on a node or integration point basis. The significance of the Local Node Input used during postprocessing depends on whether element based outputs are stored on a node or integration point basis (e).
Data Storage Points:	The number of data storage points per element. This can have a value of 1 (element mid-point only), 2 (element start and end-points) or 3 (element start, middle and end-points). See Note (f).

Notes

(a)This table allows you to customise the contents of the motion and force database files that are produced by a Flexcom analysis. By reducing the number of parameters that are output to the database files, and the number of elements for which those parameters are output, it is possible to substantially reduce the size of the database files produced. This can be particularly useful for large models and/or long simulation runtimes, especially if only a particular section of the model or certain parameters are of interest.

(b)If requested, Flexcom automatically calculates statistical parameters (minimum, maximum, mean and standard deviation) during dynamic analyses for nodal positions and certain element restoring forces (effective tensions, local-y and local-z-shear forces, torque moments, and local-y and local-z bending moments) while the analysis is running. These results are shown in the main analysis output file (jobname.out) at the end of the analysis.

Additionally, these statistical parameters are written to the database files. This may be useful for analyses with long simulation runtimes where subsequently generating statistics using the database postprocessor can take a long time. If runtime-generated statistics have been included in the database files, and you subsequently request a plot of statistics using the database postprocessor, the postprocessor checks if the relevant data is included in the runtime statistics. If it is, the relevant data is simply read from the database files; if it is not, the database postprocessor must scan the database files to calculate the relevant statistical parameters. Including runtime-generated statistics in the database files can save a considerable amount of time during subsequent postprocessing, although this is at the expense of increased database file size.

If output of statistics is selected, statistical parameters are output for nodal motions (provided additionally that nodal motions are selected for output) and each of the element restoring forces that have been selected for output to the database files. Furthermore, statistics are output only for nodes and elements for which output to the database is specified (see Note (c)). The Statistics Start Time option allows you to specify at what point during the analysis calculation of statistics should commence. Flexcom excludes any values before this time. This allows you to exclude initial transients from statistical calculations.

(c)Data should only be entered into this table when database output is requested. Any data entered here only takes effect if the Database Request table is also present.

(d)This type of output is automatically suppressed if no plastic hardening models are associated with any element sets.

(e)This option is relevant to results that are calculated at the integration points, such as generalised strains and stresses. Motions, velocities, accelerations and reactions of any kind are still calculated and outputted at the relevant nodes. If this option is set to Integration points, then the parameters are stored in the force database file directly as calculated at integration points, without any smoothing. This type output can be used for testing purposes and is relevant only for elements with three integration points. If this option is set to Nodes, then the parameters are exported from the integration points to the nodes and middle of the element. They are ultimately smoothed based on the element connectivity in the mesh and stored in the force database file. This is the default option and is independent of the number of integration points specified for the element.

(f)By default, 3 data storage points are used for every element, ensuring full data storage. Using a reduced storage scheme can significantly reduce disk space however, potentially reducing the size of the force database file by over 60% if data is stored at element mid-points only. Note that this option is only relevant when results are stored on a nodal basis rather than integration points.

(g)Flexcom uses a convected coordinate axes technique for modelling finite rotations in three dimensions. Each element of the finite element discretisation has a convected axis system associated with it, which moves with the element as it displaces in space. Refer to Finite Element Formulation for further details. The Convected Coordinate Axes option here stores the local convected axes for each element as a function of time in the motion database file.