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[CIM/Infor-Base] Understanding the Curve library


What can be modeled in Curve Library?



In Curve Library Mode, structures whose shape changes according to alignment changes such as slabs, median strips, and crossbeams can be modeled.


The modeling in CIM is based on libraries.
This is the basic composition method of the Curve Library, which is one of the library components.


1. When performing the Base > Library > Curve > Create action, the setting screen appears, and the Default Constraint Path of Unit Length and the Constraint Planes at both ends of the Path are created.

2. In the default setting of the Curve Library, you can define the name of the library, the unit length of the library, and the direction of the library.

3. The direction is set based on the global coordinates of the modeling window and can be set in the global +X, +Y, +Z, -X, -Y, -Z directions from the GCS origin (0,0,0).

The model space of the Curve Library is a modeling space based on alignment or length. It is a basic unit-length modeling space to be applied to the Assembly Unit or Base Mode (Layout or Line) of a higher-level concept.

Figure. 2 Models created in the Curve Library

Models that are affected by alignment changes such as slabs, median strips, girders, cables and railings on cable-stayed bridges, as well as models that are created based on sections and alignment, are created in Curve Library Mode.

Create a model based on it in Curve Library Mode.

Objects created in Curve Library Mode can have Constraint information through two types of Linked Entity functions. Objects that do not have constraint information exist only in Curve Library Mode and do not appear when assigned.

The types of Linked Entity are as follows.


Linked Entity type of Curve Library
Path Linked Entity
: 1D object that has a constraint on a single Main Path and is created based on section and path information. The shape of these objects changes according to the shape of the Main Path
assigned to the alignment.
Point Linked Entity
: An object with a single Constraint Point and Constraint that only changes position and is dependent on the position of the Constraint Point without any shape variation. (When using the Point Library Import function in Curve Library Mode, it becomes a Point Linked Entity.)


It is possible to configure a model in Curve Library by importing a Point Library model. However, this only imports the information in the model and does not establish a linkage between the point library and the curve library. As a result, any updates made to the Point Library model will not be reflected in the Curve Library model.


Constraint Entity that can be created in Curve Library Mode
Constraint Plane
: It is used for Main Path creation and defines the location and alignment rules of the Start/End Points of each Main Path.
Main Path
: It is utilized for creating Path Linked Entity and allows for the creation of Constraint Points for Point Linked Entity on the Main Path. The overall shape of the Curve Library is determined by the shape of the Main Path when it is assigned to the alignment. It has Offset information (Y, Z).
Constraint Point
: It is used as a reference point for defining an object to be placed at a single point on the alignment as a Point Linked Entity.
Constraint Array Point
: It is used as an Array reference point of objects to be arranged according to the Arrangement
 rule on the alignment. It is used as the Array reference point for objects arranged on the alignment according to arrangement rules.


You can find a detailed explanation of the Constraint Entity in the corresponding technical document.
Understanding the Constraint Entity(Plane)
Understanding the Constraint Entity(Path)  
Understanding the Constraint Entity(Point)

Shown below is an example of modeling a PSC BOX with a unit length of 50m using a Curve Library and assigning it to a layout.

Figure. 3 Curve Library (10m unit length PSC BOX super-structure)

Figure 3 is an example of modeling a PSC BOX in the Curve Library mode with a unit length of 50m. (The constraint plane is set to accommodate changes in length in the center of the span.)

Figure. 4 Base Mode (PSC BOX model assigned to curved layout)

Figure 4. shows the Curve Library model of Figure 3. assigned to curved layouts of different lengths in Base Mode.

The following video is an example of changing the configuration of a PSC box model by simply changing the location of the constraint plane.

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