5. Moving Load & Moving Mass- Two-span Bridge

A Time History analysis (MOVING LOAD) for a simple structure including damping is described in this Demo Example and compared with the results documented by PETERSON (Peterson – Dynamik der Baukonstruktionen, München).

The structural system intends to simulate a steel composite bridge:

In this example the User will be able to learn:

• Load and mass definition;
• Creation of the variables for the moving load;
• Calculation of the first 10 eigen modes;
• Time History Calculation including damping.

For natural frequencies, the results obtained were the ones presented in the bellow table:

And for static and dynamic load cases calculated by using Time History Analysis, results are the following:

Time History Plot - Moving Load DYNAMIC ANALYSIS (LC800)

Time History Plot - Moving Load STATIC ANALYSIS (LC 900)

The RM results for the internal frequencies and for the vertical displacement caused by a moving load compare very closely with those documented by Petersen.