Consider a beam loaded with self weight (SW), dead loads (D) and life load (L). According to EN 1990-1-1, the following safety factors apply:
- on selfweight and dead loads: 1.35 and 1
- on the life load: 1.50 and 1.
Resulting in the these 8 combinations:
ULS FC 1: 1,35 SW + 1,35 D + 1,5 L
ULS FC2: 1,35 SW + 1,00 D + 1,5 L
ULS FC3: 1,00 SW + 1,35 D + 1,5 L
ULS FC4: 1,00 SW + 1,00 D + 1,5 L
ULS FC5: 1,35 SW + 1,35 D + 0,0 L
ULS FC6: 1,35 SW + 1,00 D + 0,0 L
ULS FC7: 1,00 SW + 1,35 D + 0,0 L
ULS FC8: 1,00 SW + 1,00 D + 0,0 L
Assume all loads are vertical downward than
- the maximum bending moment, shear force, deflection and reactions will be found in ULS FC1.
- the minimum bending moment, shear force, deflection and reactions will be found in ULS FC8.
An envelop result is the collection of all minimum and maximum results. So for the beam above, all the results from ULS FC 1 and ULS FC8 will be shown in th envelop. This way, you don’t have to go through all the combinations seperatly to find the maximum result.
