Calculating mass rollup

Rollup calculations are used to find the total mass based on the individual masses of all the parts in the structure (or the selected assembly). However, you can perform these calculations only when Weight and Balance Management is set up in your Teamcenter environment.

You can use the following templates to perform rollup calculations:

• Mass Properties – Rolls up the mass of the components in the structure.
• Mass and Balance Properties – Rolls up the mass as well as the balance values of the structure components such as Center of Mass, Moment of Inertia, or Product of Inertia.
• TC default rollup template – Default template to create comma-separated rollup reports for mass, Center of Mass, Moment of Inertia, or Product of Inertia. Rollup is based on the Design mass and not on the precedence order.

Your administrator manages the column configuration in a rollup report. However, you can have your own column configuration by overriding the WNB0_MassPropsColConfiguration and WNB0_MassAndBalancePropsColConfiguration preferences.

Your administrator specifies the rollup unit of measure (UOM) for your site. The rollup action always generates the rolled up value in this specified UOM. The rolled up value is listed in the Computed column in the rollup report.

You can use the following mass types for rollup calculations:

• Actual
• Asserted
• Evaluated
• Budgeted
• From Design

Your administrator can add custom mass types for your site. As an authorized user, you can add values for the Actual, Asserted, and Evaluated mass types. However, you can enter or edit the value for the Budgeted mass type only if you are a privileged user. Your site administrator assigns the user privileges using Access Control.

The value for the From Design mass type is retrieved from the CAD tool, and it cannot be edited in Active Workspace.

Each mass type can have a different value. This implies that structure components can have multiple mass values. In such cases, the mass value for a rollup calculation is selected based on the maturity assigned to the associated mass types.

Understanding rollup calculation

In rollup reports, such as mass, Center of Mass (CoM), Moment of Inertia (MoI), Product of Inertia (PoI), area, and volume, Teamcenter shows individual component property values as single-unit values rather than multiplying those values by their quantities at the component level. That is, for the individual components in an assembly, Teamcenter displays the property value of one unit only.

There is no multiplication with quantity. Quantity is considered only in the context of a parent assembly, and not at the individual component level. For the parent assembly, Teamcenter considers the quantities of child components for the rollup calculation of the total assembly.

Example

Consider that an aircraft brake system contains the following component structure:

• Aircraft Brake System
  • Brake Assembly (Quantity: 4, Asserted Mass: 6.3 Kg each)
    • Brake Disc (Quantity: 2, Actual Mass: 1.5 Kg each)
    • Brake Caliper (Quantity: 2, Actual Mass: 1.2 Kg each)
    • Connector (Quantity: 3, Actual Mass: 0.3 Kg each)

In the mass rollup report, for Connector, the rolled-up value is shown as 0.3 Kg. And for the Brake Assembly, the rolled-up value is shown as 6.3 Kg. The Brake System has 4 Brake Assemblies. So, for the Brake System, a weight engineer can calculate the total mass value as 4 × 6.3 = 25.2 Kg.