Applying point, line, and area loads to bridge objects
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Model description
Create a new model from template. Define as a simple span, 40m long, with steel girders cross-section.
Release the bearing at the end abutment to achieve a simply supported condition.
Define point, line, and area loads in separate load cases as follows:
Point load: 10kN load applied at station 20, centered transversely.
Line load: 1kN/m load applied between stations 15 and 25, centered transversely.
Area load: 0.1kN/m^2 load applied between stations 15 to 25 and across the width of the deck.
These loads will all cause an effect equivalent to loading the bridge midspan with a 10kN point load
Run the analysis and check the midspan moments. For point loading, the theoretical midspan moment is given as follows:
Plan, elevation, and section diagrams depicting load application are given in Figure 1:
Figure 1 - Load application diagrams
Model development
Define and apply loads
Use the Loads > Loads - Point command to define a new point load, as shown in Figure 2:
Figure 2 - Define point load
Use the Bridge > Loads > Point Loads command to assign the previously defined point load, as shown in Figure 3:
Figure 3 - Assign point load
Using a similar approach, define and apply line and area loads.
Results
The moment diagrams below (Figures 4-6) depict the midspan moment expected.
Figure 4 - Point load moment diagram
Figure 5 - Line load moment diagram
Figure 6 - Area load moment diagram
Attachments
CSiBridge V15.0.0 model (zipped .SDB file)
Metadata
Name: Applying point, line, and area loads to bridge objects
Description: This tutorial demonstrates point-, line-, and area-load application to bridge objects.
Program: CSiBridge
Program Version: 15.0.0
Model ID: na