Defining the mass group parameters

In the editing dialogue, parameters of a particular mass group may be edited.

Name	Defined a name of mass group.
Description	A user description of mass group.
Bound to load case	Yes - s particular load case can be assigned to the mass group No - the mass groups is not connected to any load case
Load case	Here, the user may select a load case that should be used for an automatic generation of masses.
Keep masses up-to-date with loads	If ON, masses are automatically updated according to all changes of load in the selected load case.
Delete all masses	This button removes all masses (input and generated ones) from mass group.
Create masses from load case	This button tells the program to generate masses from all load defined in the load case specified above.

A few notes concerning the generation of masses from load case

Mass from self-weight is created EVERY TIME and is NOT displayed.

Masses from other load cases are generated on pressing button [Create masses from load case] from the load case adjusted in the dialogue.

They are created only once! (If the button is pressed again for the same load case, nothing happens).

On the other hand, it is possible to add masses from different load cases. Or more precisely, masses are added according to the following criterion: if a mass has been already created from a force in a node, no other mass (created) from a force is added to this particular node, even though the force is (created) from another load case.

The mass remains unchanged after any modification or removal of the original force. If the mass is supposed to correspond to the modified force, it is necessary to remove the mass and create it once more.

The mass is generated ONLY from vertical force component – horizontal forces would create no mass at all.

Only the load that is defined on an object (member, node, point on a member, etc.) is considered in the generation of masses. Free loads are NOT taken into account!

Conversion formula used: m * g = F (default value is g = 9.81).

The display of masses in controlled by a separate view parameter (pop-up menu function Set view parameters/all) and is independent on the displayed load case.

Masses are also displayed (by default setting) in the service Masses. Therefore is probably the best approach to generate masses from within this service.

The calculation module concentrates masses into nodes, therefore finer mesh is required. For example, part of the mass in a node with support "will disappear" (produces no response). If the mesh is fine enough, this arrangement has no negative influence on the accuracy of results. However, apparent irregularities may appear if coarse mesh is used and the user wants to compare the results of this rough calculation with manually obtained values.

Example

Below there are two pictures. The first one with line loads defined. The other one then demonstrates the masses generated automatically from that load.