Column calculation

The purpose of the Column calculation project is to check columns for a steel cross section group under double bending taking into account shear and axial forces including stability check. Redistribution of internal bending forces (moments and shear forces) in the column is calculated taken into account trapezium distributed load over the column length and concentrated moments on the begin/end of the column.

 

Position of the local axes y'-y' and z'-z' in a cross section:

Position of local axes in a cross section

 

General options:

Option

Unit

Description

Section/Section group

-

List of available sections is supported by EN1993-1-1 and related national annexes such as NEN-EN1993-1-1. Items listed in the Section/Section group drop down list depend on chosen code or/and national annex

Material

-

Steel material name is using for code check calculation and supported by EN 1993-1-1#Table 3.1 and related national annexes such as NEN-EN1993-1-1#3.1. Items listed in a Material drop down list depend on chosen code or/and national annex

 

Column calculation input parameters:

Parameter

Unit

Description

L | lsys

m

Member length

Nc;Ed | Nc;s;d

kN

Design value of the axial force in direction of local x-x axis. Negative sign of axial force is representing axial compression, positive – axial tension

q in A, q in B

kN/m

Design value of a trapezium distributed load along local y’-y’ or z’-z’ axis on begin (A) and/or end (B) of the column. Is not supported different sign of the q load on begin and/or end of the column

MEd | Ms;d for A, MEd | Ms;d for B

kNm

Design value of a bending moment around local y’-y’ or z’-z’ axis on begin (A) and/or end (B) of the column

Buckling system

-

User choice:

a) Conservative braced with (Lcr | leff) = (L | lsys) as default;

b) Braced with calculated Lcr | leff using CA and CB as user input;

c) Sway with calculated Lcr | leff using CA and CB as user input;

d) User with L | lsys as user defined value

CA and CB

-

User defined supporting parameter of the column around local y’-y’ or z’-z’ axis on begin (A) and end (B) of the column.

Values of CA and CB are acting on calculation of Lcr | leff only in case Buckling system as Braced or Sway is chosen.

Calculation of Lcr | leff using CA and CB is based on the rules defined in NEN6770#12.1.1.3

Lcr | leff

m

Buckling length could be:

a) ( Lcr | leff) = (L | lsys) as default in case Buckling system is chosen as Conservative braced;

b) Lcr | leff is calculated using CA and CB in case Buckling system is chosen as Braced;

c) Lcr | leff is calculated using CA and CB in case Buckling system is chosen as Sway;

d) L | lsys is user defined value in case Buckling system is chosen as User.

 

Calculation of Lcr | leff using CA and CB is based on the rules defined in NEN6770#12.1.1.3.

For the braced column Lcr | leff is less or equal to 2* (L | lsys).

Value of (Lcr | leff) / (L | lsys) calculated using CA and CB for sway column in range of 1 and ∞

lg

m

Length of the column could be also supported by lateral supports. lg should be not less than L | lsys

Column length supported by lateral supports

For detailed information look NEN6771#12.2.5.3

Lat. Buckling supports (Top):LC, Lat. Buckling supports (Bottom):LC

m

Absolute distances/position(s) of lateral supports from begin of the column respectively on the top and/or bottom of the column cross section. Position(s) of lateral supports should be separated by ";" if defined. Defined position of the lateral support should be not more than value of L | lsys

C1

-

Factor used for estimation of buckling properties for the column (beam) depends on shape of the loading.

For detailed information look NEN6771#12.2.5.3

C2

-

Factor used for estimation of buckling properties for the column (beam) depends on load attachment respectively neutral axis of the cross section.

For detailed information look NEN6771#12.2.5.3

Llat buck

m

Length of the column (member) part, where decisive buckling moment is found.

Length of the column (member) part, where decisive buckling moment is found

For detailed information look NEN6771#12.2.5.3

Field

-

Identifier of the field of the column (member) part, where decisive buckling moment is found.

For detailed information look NEN6771#12.2.5.3

H acting

-

Load attachment respectively neutral axis of the cross section. Load attachment influences value of the factor C2. Load attachment could be set as following:

a) Upper flange +10%;

b) Upper flange;

c) Center (on neutral axis of cross section);

d) Lower flange;

e) Lower flange +10%;

For detailed information look NEN6771#12.2.5.3

 

The notations separated by "|" respectively represents the values for EN 1993-1-1 (or related national annex) and NEN 6770 / NEN 6771