load nature of a load combination

[Mohamed_AbdElAziz4TPC2]

I  noticed that  a manual load combination can be assigned a load nature and sub-nature

I don’t understand this concept since a combination consists of various loads with different natures dead, seismic ..etc

By default it is assigned with nature dead and sub-nature structural should I leave it as it is ?

I noticed dramatic changes when assigned seismic nature for example.

[Krzysztof_Wasik · Accepted solution]

Hi @Mohamed_AbdElAziz4TPC2 

Subnatures are used while generation of automatic combinations. For instance in Eurocode there are different types of live load categories A-E (with different coefficients recommended). Subnature allows for live load definition with required Category.

[Mohamed_AbdElAziz4TPC2]

thank you @Krzysztof_Wasik