Two members have been assigned the same section HE800B and the loading on the member applied are also similar, which is compression and bending. However, one of the members have been classified as CLASS 1 and the other has been classified as CLASS 4. Why?
The section-classification of sections as per EN 1993-1-1:2005, Table 5.2, for bending and compression of both the Internal Compression Parts and Outstand Flanges depends on the values of α and Ψ, which in turn are used to determine the c/t ratio. These parameters are dependent on the intensity of the loads and thus the section classification cannot be expected to be the same even if the sections are same and similar loading has been applied on the members. The intensity of loading also plays a prominent role.