Risposta:
Il motivo della differenza nei risultati tra la sovrapposizione di CC in CO e RC è che quando si applicano i carichi tutti in una volta in un CO, si ottiene una distribuzione del carico diversa in tutta la struttura rispetto a CA, dove i risultati sono sommati. This is based on FEA, where adding all of the loading together is different compared to solving the LCs individually and adding the results together. You can compare it to a different order of operations, to put it simply. You can see the comparison in the two images below. Image 02 has the load cases added up in CO1 and Image 01 has the LCs added together in RC1.
Differences in results can also be cause by nonlinear elements introduced in the model. For example, Tension Only members could be deactivated in a LC but activated in a CO because of loading changes. Keep nonlinear elements in mind when adding LCs together in a result combination, as results of failing objects will be set to zero during the super-positioning of the individual load cases. This could lead to unexpected results.
