Point-point connection (Geometry)

Point-point connection property	Description
Icon
Modules where available
Motion component direction	Parallel with Global Z axis in
	Arbitrary direction in Global XY plane in
	Arbitrary direction in
Rotation component direction	Arbitrary direction in Global XY plane in
	Not available in
	Arbitrary direction in
Geometry	- (insertion points)
Available analysis results	Connection forces and moments
Default Short Command	CPT

Point-point connection

With Point-point connection, different connections can be defined between crossed or connected bars. It is very useful in 3D modules. Some typical examples:

• Bracing (called St Andrew’s cross)
  A hinged connection between two channels intersecting each other: free rotation around the axis perpendicular to the plane defined by the two channels. (It is not necessary to define the eccentricity; the next figure is schematic.)
  
   

• Independent bars
  Defining two bars crossed each other with their structural lines but having no connection in real state is a typical problem of modeling. Now, it can be solved easily by creating point-point connection in the bars' intersection with all components set to “free”.
  
   
• Semi-rigid connection between members
  At the Connections settings of members (Bar > Default settings) only fully rigid or different type of hinged end connections can be defined. But, Point-point connection command gives the possibility to model any other connection types like semi-rigid connection with given stiffness values for rotation. The stiffness values can be set according to the applied standard instructions.
  
   
• “Real state” modeling
  Real eccentric position (e.g. bars connected with their web plates) without eccentricity settings can be also modeled with Point-point connection.
  

Definition steps

1. Start  Point-point connection command from tabmenu and choose Define.
   
    
2. Set the properties of the new connection at  Default settings. See the settings possibilities and options at Properties (Non-Linear Behaviors).
   

    

   Applying a connection different from rigid state, the Interface position (r) is very important. r = distance between connection position and start point of definition / distance between start and end points of connection

   The next figure introduces the meaning of the interface position (r) (it has no effect if the connection points are in the same position!):
   

3. Set the system for the direction of the connection components.

4. Select the first object you would like to connect.

5. Define the point of the first object you would like to start the connection.

6. Define the point of the second object you would like to end the connection. If the connection points between the two objects (crossed each other) are in the same position, just click   to define the connection end point.

Optional steps:

7. Modify the connection properties with the  Properties tool of the tool palette.
8. Add members to a selected connection or remove members from it with  Edit connected objects.

   The next figure shows the steps of adding a new member (beam) to a predefined point-point connection. First, select the connection you would like to modify and then choose the new object you would like to add to the selected connection. To remove a member of a connection, do the same steps with  .

   The next figure shows you the difference between the static-systems of the initial and modified states at all rigid bar end connections and defined hinged point-point connection.
   

9. Set the display settings of connections at Settings > All > Display > Connections.

   “Label” represents the connections’ ID number generated by analysis/design calculation or by clicking Refresh numbering (Tools menu).

10. The connections are stored on “Modeling tools” Object layers. At layer settings, the default color defines the connection label color.
    Each connection element has its own local system. The connection symbol (darker colors, thicker lines etc.) shows the objects having one of the associated above mentioned connection types.
    
    The following figure shows an example how the program makes different symbols depending on what object was selected during the selection of the connected points. But note, that although the definition ways are differ at the column-plate connections, if the properties (directions, components and stiffness values) are the same at both point-point connections (here in the example, hinged connection = all rotation components are free), the static-systems are also the same.