Changing stiffness in TALPA

I have a beam model of a tunnel cross section, which I run in TALPA to capture soil interaction during the construction phases.

each structural part (base, walls and roof) is discretized by several beam elements and grouped together afterwards.

I would like to change the stiffness in a few of the beam elements during the construction phases, e.g. the midspan element of the roof slab. However, as TALPA only allows me to change parameters of groups, and not by individual elements, this doesn’t seem possible?

Is there a clever way around this, rather than grouping each discretized element individually?
This would be a major inconvenience and defeats the whole purpose of grouping elements in the first place.

I’ve tried using secondary groups but TALPA doesn’t allow that either.



As far as I know the only way to change the element stiffness during the calculation is with the commands GRP or CGRP.

But I do not understand why you have to group every individual element. You can group multiple elements at once within SOFiMSHC or SOFiMSHA.

See our TALPA examples for more details.

TEDDY > File > Examples > talpa > tunnel > tunnel-embedded.dat

Best regards
Frederik Höller
Your SOFiSTiK Support Team


Thank you for your reply.
The reason why I need to group the individually is because the elements in which I need to vary parameters change with each analysis I run. (I’ve set up a Python script to run the model with different parameters).

I have set up a workaround in python to define groups based on my requirements, but I would be a lot easier if I could just change the parameters based on element number instead of groups.

Please see the example figure I’ve made below.
The grouping leads to conflict in run 2 and 3 as an element is shared.