Hello,

I'm performing a form-finding (in which I need to consider a certain number of applied loads DURING the FF procedure, so I activated the specific FF load case).

After the form finding I need to perform the various code-checks so I activated the automatic generation of load combinations.

I found that the obtained results are not "automatically" correct: for instance for the serviceability limit state that consider only the self-weight (defined in load condition LC1 - self-weight) the "apparent combination" is

SLSa = LC1

This is correct, but in truth, the form-finding procedures is already accounting for the loads defined in the FF load case, and thus the "real combination" is

SLSr = SLSa + FF = LC1 + FF

The SLS combination is then not correct.

All other SLS and ULS combinations are, in fact considering the "apparent combination" PLUS the previous FF load case (implicitly present in the form-finding starting solution).

One possibility is to disable completely the automatic calculation of load combinations, and manually entering combination coefficients.

A general solution would be to define the "apparent combination" by SUBTRACTING the FF loads before adding all other loads. For instance for the SLS case defined before, I would obtain the "apparent combination":

SLSa = LC1 - FF

that would give the correct results, being the starting configuration based on FF, and thus the "real combination" is

SLSr = SLSa + FF = LC1 - FF + FF = LC1

I hope I've been sufficiently clear. Maybe there is already an option available to solve this issue: have you any suggestion?

Thanks in advance

Andy

I'm performing a form-finding (in which I need to consider a certain number of applied loads DURING the FF procedure, so I activated the specific FF load case).

After the form finding I need to perform the various code-checks so I activated the automatic generation of load combinations.

I found that the obtained results are not "automatically" correct: for instance for the serviceability limit state that consider only the self-weight (defined in load condition LC1 - self-weight) the "apparent combination" is

SLSa = LC1

This is correct, but in truth, the form-finding procedures is already accounting for the loads defined in the FF load case, and thus the "real combination" is

SLSr = SLSa + FF = LC1 + FF

The SLS combination is then not correct.

All other SLS and ULS combinations are, in fact considering the "apparent combination" PLUS the previous FF load case (implicitly present in the form-finding starting solution).

One possibility is to disable completely the automatic calculation of load combinations, and manually entering combination coefficients.

A general solution would be to define the "apparent combination" by SUBTRACTING the FF loads before adding all other loads. For instance for the SLS case defined before, I would obtain the "apparent combination":

SLSa = LC1 - FF

that would give the correct results, being the starting configuration based on FF, and thus the "real combination" is

SLSr = SLSa + FF = LC1 - FF + FF = LC1

I hope I've been sufficiently clear. Maybe there is already an option available to solve this issue: have you any suggestion?

Thanks in advance

Andy

## Kommentar