How can I export envelopes for a specific force (e.g. maximum bending moment) and obtain the concurrent forces associated with that force for a group of elements (e.g. longitudinal beam consisting of several frame elements) in an integral bridge model in MIDAS? 

Answer:

You can obtain the concurrent forces in a table format in results tables. For this:

1. Activate the Normal + Concurrent forces to be saved from the Analysis >> Moving Load Analysis Control and re-analyse the model:

2. Go to Results >> Result Tables, select the beams and moving load cases you are interested in to generate the table. This will be based on the envelopes as you have indicated. Right-click in the table and choose View by Max Value Item:

3. Select the leading components and load cases and a new table with concurrent forces will be generated: