Mass Properties

Common Functionality User Guide

Data Check : Mass Properties : Mass Properties

The Model Query group allows the user to calculate mass properties, such as the weight and centre of gravity, the volume and the surface area for any part of the design model.

On the Tools tab, in the Model Query group, click Volume to display the Volume window.

Each of the Model Query group windows are divided into parts, these are common to Weight CofG, Area and Volume.

The top section of the window is used to add elements for mass property calculations.

Add Elements

Add Elements has the following drop-down menu options:


Current Element	Adds the current element.
Element Members	Adds all members of the current element individually.
Members with Tubing	Adds all members plus the tubing elements also.
Current Collection	Adds all elements as listed in Collections.
Graphical Pick	The user is prompted to graphically pick elements in the 3D view.
Graphical Selection	Using the standard graphical select mechanism, this option adds all currently selected elements.
Within Area	Prompts the user to graphically pick an area then adds all elements within that area to the Selection Grid.
Within Volume of CE	Everything enclosed within the specified/selected area/zone.

Named Element

A known element can be typed in the Named Element box and applied to the Selection grid by clicking Add.

Selected Elements

The Selected Elements grid is a multi select list of elements. Right-click on a selection to display a pop-up menu with the following options:


Remove Selected Element(s)	Removes all selected rows from the grid. Recalculation is necessary.
Remove All Elements	Remove everything from the grid.
Enhance in 3D View	Highlights in colour the selected element.
Unenhance in 3D View	Unhighlights the selected element.
Navigate to	It is a toggle, which when ON navigates to the selected element in the explorer, making it the new current element.
Export to Excel	Allows the user to save the grid data in an excel file. The file is automatically named using the time and date with relevant text Volume/Surface/Weight. saved in the AVEVA_DESIGN_USER folder.
Print Preview	Allows the user to preview and print the calculated data.

Settings

The lower part of the windows has options for specific Mass Property Settings. The main Settings determine if the calculations are to consider negatives (holes/cut-outs):

Negatives

The following options are available from the Negatives drop-down list:


Consider (Net)	Considers all holes when calculating the mass property.
Ignore (Gross)	Ignores all holes when calculating the mass property.
Ignore (Rough)	Ignores all holes when calculating the mass property. The specific meaning of ‘rough’ as opposed the ‘gross’ is that rough is a quicker calculation. It is sometimes useful for large amounts of data or components with complex shapes.

A good example of choosing to use Consider(Net) or Ignore(Gross) is a steel plate panel with a hole, where a ‘net’ calculation gives the finished weight; but a ‘gross’ calculation gives the weight of the panel before the hole is cut.

Volume of

Element Only verses Element plus members.

The 'Volume of' ('Weight of' or 'Surface of' for other windows) is mainly to allow reporting of elements that may have geometry, and own other elements that also have geometry. A good example is a steel section (SCTN) that owns a fitting (FITT).


Element only	Considers the geometry of the element only
All Members	considers the element plus the geometry of all of the element members

for example:

Weight of SCTN only = 1000kg

Weight of SCTN + FITT = 1057kg

Representation Level

When calculating any Mass Property, the system uses the Representation Mass value, input in the representation level field or set using the Setting > Graphics > Representation window. Representation Mass is similar to other representation settings for different drawing levels of detail of a pipe component or equipment. For example, a very simple shape at say level 1 for a quick calculation of surface area rather than a very complicated set of detailed shapes that would mean a very complex (hence slower) calculation of the surface.


	The Apply Representation Rule Set

Units

Both metric and imperial units can be selected from the pull-down menu in Volume and Surface window.

Note:

Not available in Weight and Centre of Gravity (CofG) window.

Within Area

It is possible to calculate the Mass property of each element in the Selection grid:

Note:

Not available in Weight and Centre of Gravity (CofG) window.

•

Volume/Surface inside

•

Volume/Surface outside

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Free Volume inside (Volume window only)

If this option is to be used, then selecting the check box makes the gadgets active for input, or picking, of an ‘Area Definition’ AREADE such as a room; then specifically ‘inside’ or ‘outside’. It is possible to calculate the weight of all the elements within an area (AREADE) by adding the elements within an area to the list of elements to be processed then performing the calculation on only these elements.

Each option allows for setting and refreshing of the representation level to be used in the Mass Property calculation.

Centre of Gravity Setting

For Weight and Centre of Gravity Mass Properties only there are two additional setting options:

•

Wet/Dry

•

CofG WRT.

The Wet/Dry option for Dry weight and Wet weight, is used primarily for Piping and Equipment with fluids.


Dry Weight	Normal Component weight.
Wet Weight	Considers the fluid for pipes.

For Equipment the weight is normally an input value USRWEIGHT with an optional USRWWEIGHT for wet weight.

The CofG WRT option is used to calculate the centre of gravity of an element with respect to another element.

The user can input, for example an Element Name and Calculate uses this for the list of individual Centres of Gravity. If the user changes the CofG WRT value only the total Centre of Gravity is refreshed. To refresh the individual Centre of Gravity the user must click Apply again.

Calculate

To calculate any of the settings applied in the Volume, Surface or Weight and Centre of Gravity window the user must click Apply.