Hello everyone,
For my thesis, I am analysing skewed slab bridges in RFEM. As a starting point I have created load cases for traffic loading, thermal loading, and self-weight.
For the traffic loading, the carriageway is divided into lanes. In each lane, I place the corresponding Tandem System (TS) load at several different longitudinal positions (for now only 3 - beginning, middle, and end), together with the associated UDL for that lane.
My goal is to determine which TS position is governing for the internal forces. To achieve this, I created a Result Combination in which the TS load cases within each lane are assigned the OR operator, so that the governing TS position for each lane can be found.
Here is my Result Combination:
After running the calculation, the envelope results show the governing internal forces. The corresponding load cases that produce the envelope value can also be seen:
To verify the result, I manually created a Load Combination using exactly the same load cases reported by the envelope. However, the resulting internal force (in this case my,d+) does not match the envelope value found from the result combination
Load Case:
Results from load case:
Has anyone experienced this before?
Is there something I'm misunderstanding about how to correctly use Result Combinations?
Any advice or suggestions would be greatly appreciated.
Thank you!
Here is the model in case it is needed:
RFEM Result Combination Envelope Values.rf6 (1.2 MB)