Frame30 – Moving Loads
- Gokhan Alkan (Unlicensed)
Example Description
This example uses a 40-foot-long simple span bridge (beam) to test moving load load cases. Moving load cases use defined vehicle loads and defined lanes (rather than the load cases that are used by other analysis types) to calculate the most severe response resulting from vehicle live loads moving along lanes on the structure.
A single 12-foot-wide lane with a maximum discretization length of 2 feet is defined along the center line of the bridge structure. An H20-44 truck load vehicle and an H20-44L lane load vehicle are created and a vehicle class containing both the H20-44 and H20-44L vehicles is defined. The moving load analysis considers both vehicles separately and reports the worst-case response.
In addition to the moving load case, this example also includes a multi-step static analysis for the H20-44 vehicle. This analysis simulates the truck moving across the bridge.
For each of the load cases the maximum moment and maximum reaction are compared with independent results that are either presented in Appendix A of AASHTO 1990 or hand calculated.
Output stations along the frame element modeling the bridge are specified to be at a maximum spacing of 2 feet.
Tested Features
- Moving load case
- Multi-step static load case for vehicles