Load Group – Titles and Code Designation

British and European Codes of Practice demand that structures are designed to sustain dead, live, wind and notional loads under both service and ultimate conditions. These loads are combined using various load factors to produce a variety of loading cases. It is essential therefore to differentiate between the various types of loads applied to the frame so that they can easily be combined to produce any number of loading cases.

In many instances, it is necessary not only to distinguish between dead, live and wind loading but also between various types in each category. For example, when considering the design of concrete beams under alternate loading, it will be necessary to differentiate between the dead load on odd spans (1, 3, 5, .. etc.) and on even spans (2, 4, 6, .. etc.). The same rule applies to the live loads. In portal frames you may need to distinguish between side wind with internal suction, side wind with internal pressure, gable wind with internal suction and gable wind with internal pressure.

MasterSeries enables you to distinguish between the various types of loads using a set of 141 load groups with unique labels as follows:

D0 to D9,    L0 to L9,   W0 to W9,   N0 to N9,   A0 to A9,   B0 to B9,   C0 to C9,   E0 to E9,   F0 to F9,   G0 to G9,   H0 to H9,   I0 to I9,   J0 to J9,   K0 to K9   and   UT.

The UT is the Unity Load factor for loads and other conditions which apply in all loading cases. Usually all Nodal Supports are defined with a UT Load Group.  A Nodal Support is no different from any other load in that it will only be active in a loading case if it’s Load Group is active (i.e. not zero) in the Loading Case. The default Nodal Support Load Group UT is active in all Loading Cases and means that the support is always present.

Each load group can be given a title to describe the loads under its umbrella. It is important to understand that a Load Group can have many different shapes and intensities of load in it. The only requirement is that all loads in a single load group must all be applied to the structure at the same time and be multiplied by the same Load Factor.

A good example of a Load Group is “Wind blowing on the side of a building”.  Each face will have a different load intensity and some will be X-Axis Loads some will be N-Axis (normal to member) Loads. Indeed, some of the loads could be partial UDL’s or Triangular Loads but they are all in the same Load Group (e.g. W1) as they occur simultaneously.

To edit the load group titles, select "Load Group - Titles and Code Designations" from the Loads Menu. Under the Load Group Titles tab, you can highlight whichever load group title you want to change and overtype the title. Note that the load group number can be selected from the drop list of numbers.

For live or imposed loads to EuroCode EC0 you can choose an imposed load type from the category drop list, eg, Category B: Office.

A ratio for Ginf over Gsup, lower value of permanent action divided by the upper value of permanent action, can be entered, if required. This currently defaults to a ratio of 1.0.

To increase efficiency, you can save load group titles in a special library using the Add + button and then retrieve them from the combo list in any other project. You can delete items no longer required using the Del X button. To add the load group title to a particular group, highlight the required group, eg, W2 and then select the appropriate title from the library drop list, eg, Gable Wind.