D11.A.4.4 Compression

The compressive strength of members is based on limit states per NZS3404 Section 6. It is taken as the lesser of nominal section capacity and nominal member capacity.

D11.A.4.4.1Compression Section Strength

Nominal section capacity, φNs , is a function of form factor (Cl.6.2.2), net area of the cross section, and yield stress of the material. Through the use of the NSC parameter, you may specify the net section area. Note that this parameter is different from that corresponding to tension. The program automatically calculates the form factor. The

kf
form factors are calculated based on effective plate widths per Cl.6.2.4, and the fy yield stress is based on the minimum plate yield stress.

The NSC (net section factor for compression) design parameter is used for compression sectoin strength checks.

D11.A.4.4.2Compression Bending Strength

Nominal member capacity, φNc , is a function of nominal section capacity and member slenderness reduction factor (Cl.6.3.3). This value is calculated about both principal x and y axes. Here, you are required to supply the value of αb (Cl.6.3.3) through the ALB parameter. The effective length for the calculation of compressive strength may be provided through the use of the parameters KY, KZ, LY, and LZ.

The PBCRES and LHT design parameters are also used for this check.