# Design of Compression Elements

**Notations**

**N _{b,rd}**

**the design buekljng resistance of the compression member**

_{ }=**ꭓ**

*the reduction factor for the relevant buckling mode*

**=****α**

*imperfection factor*

_{ }=*the elastic critical force for the relevant buckling mode*

**N**_{cr}=**λ=**the in-plane non-dimensional slenderness

**f**_{y}**yield strength**

_{ }=*cross-section area*

**A =**### Uniform Members in Compression

First of all, local buckling control should be done. The calculation is made according to whether the elements are delicate or delicate. Classification of cross sections is automatically determined according to 5.4. Classification of cross sections

There are two different equations depending on classification of cross sections. Eq. 6.47 is for class 1,2, and 3 and Eq. 6.48 is for class 4.

X, reduction factor for the mode, is automatically determined according to 6.3.1.2. For the calculation of reduction factor, the imperfection factor should be determined depending on buckling curve according to Table 6.1. There are five different buckling curve in EN 1993-1-1 Figure 6.4. To select buckling curve of the cross section is determined according to Table 6.2.

for Class 1,2 and 3 cross-sections

for Class 4 cross-section

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