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[CIM/Infor-Base] Understanding the Assembly Unit


What do I model in Assembly Unit Mode?



Assembly Unit Mode is a space for assembling structures created in sub-mode.


CIM's modeling is based on the Library.

Assembly Unit is a model space for combining models from the Curve Library or Point Library and giving them to the Base Mode model.


1. During Base > Library > Assembly > Create operation, the setting screen is entered,
    and the Default Constraint Path of Unit Length and Constraint Plane at both ends of the
    path are created.
2. In the assembly unit default settings, you can define the name of the assembly unit (Name)
    and the unit length of the assembly unit (Unit Length).
3. At this time, the generated unit length is created only in the Global +X direction from
    the GCS origin (0,0,0).

Figure. 1 Assembly Unit Setting Window

The model space of the Assembly Unit is the unit length model space of the assembly stage to apply the model of the Curve Library or Point Library created in advance to the Base Mode Layout.

In Assembly Unit, you can assign (or create) each library and assemble as many group units as you want, such as span and structure.

At this time, each object must have constraint information in order to have a rule when it is assigned in alignment

There are four functions to define constraint information, Linked Entity and Assign Library.


How to define constraint information in assembly unit
Path Linked Entity
: Path Linked Entity: 1D object that has a constraint in one main path and is created based on
  section and path information. The shape changes according to the shape of the Main Path
  assigned to the alignment.
Point Linked Entity
: An object that has a constraint relationship with one constraint point or constraint array point,
  and is dependent on the position change of the constraint point without changing the shape
  and moves only the position.
Assign Point Library
: Assigns a pre-written Point Library to the Constraint Point or Constraint Array Point
  created in the Assembly Unit.
Assign Curve Library
: Assigns the pre-written Curve Library to the Constraint Path created in the Assembly Unit.

The Linked Entity function is the same as in Curve Library Mode and is utilized when creating a model directly in Assembly Unit Mode.

Objects assigned in Assembly Unit Mode through Assign Library have a link relationship with sub-modes, so they have the advantage of being automatically updated when the library is changed.

Assembly Unit Mode utilizes various Constraint Entity complexly. The types of Constraint Entity that can be created are as follows.


Constraint Entity that can be created in Assembly Unit Mode
Constraint Plane
: Entity whose arrangement in alignment changes according to Location and Alignment settings,
  used to define the shape of other entities
Main Path
: Path that changes to the same shape as alignment, used for slabs, median strips, etc.
Rigid Path
: A straight path created while maintaining a fixed length value from one constraint point and
  used for straight objects with a fixed length (PSC Beam, etc.)
Sub Path
: A straight line path in which the Start / End Point is controlled by two Constraint Points, and is
  used for straight objects whose positions of both end points change according to the alignment
  (cables of cable-stayed bridges, etc.)
Constraint Point
: Used as a constraint reference point of an object to be placed at a point on the alignment.
Constraint Array Point
: It is used as an Array reference point of objects to be arranged according to the Arrangement
  rule on the alignment.

The example below is an example of creating an assembly unit for each structure and assigning it to a layout.

Figure. 2 Assembly Unit-1 (Unit Length : 10m / Alternating assigned to both end points)

Figure 2. is the result of creating and assigning constraint points to the starting point and ending point positions of the assembly unit for the starting point shift and the ending point shift modeled with the Point Library.

The unit length of the Assembly Unit is only 10m, but the abutment located at the starting point and the end point at the 10m length based on the location is 180m alignment, considering the ratio, It will be located at the starting and ending points of the 180m alignment.

Figure. 3 Assembly Unit-2 (Unit Length : 170m / Pier assigned to each point)

Figure 3. is the result of creating and assigning a constraint point at the same location as the layout span configuration in the Assembly Unit for the pier modeled by the Point Library.

Piers are located at 55m and 115m points based on the station of the layout, respectively, when alignment allocated. In the Assign Point Library step, you can input information related to Offset and Vector from constraint points to be assigned.

Figure. 4 Assembly Unit-3 (Unit Length : 10m / upper part assigned to Main Path)

Figure 4. is the result of assigning the PSC Box superstructure model created with the Curve Library to the Assembly Unit.

The unit length of the assembly unit is 10m, but the alignment of the start/end plane of the main path in the center of the span is set to respond to the length change from alignment.

If the combined modeling as shown in the figure above is assigned to the alignment set by Base > Layout , the bridge modeling is completed as shown in figure 6 below.

Figure. 5 Create Layout

Figure. 6 Final Finished Model

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