how do i trim the member between the two plates against the column flanges.
Try using the extend extension (found on the extranet here: https://extranet.tekla.com/BC/tekla-structures-en/extensions/extend/Page...) I use it all the time for things like this. However, it will only trim the beam to the center of the column line. From there I would mess around with the "end offset" in the position tab of the beams properties box. This will allow you to keep the workpoint at the column centerline as it should be, but it will only show the beam ending at the flange like you are looking for. If you need additional help let me know and i can try to post an easy example here.
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