| Applies To | |||
| Product(s): | STAAD.Pro | ||
| Version(s): | All | ||
| Environment: | N/A | ||
| Area: | Steel Design Codes | ||
| Subarea: |
EN 1993-1-1:2005 | ||
| Original Author: | Bentley Technical Support Group | ||
C1:
This parameter allows the user to specify the C1 parameter, which is used in the equation of the calculation of the Elastic Critical Buckling Moment, Mcr –which has been referred to in clause 6.3.2.2 of the EN 1993-1-1:2005 code. This equation can be seen in Annex F of the DD ENV code. This parameter would allow the user to overwrite the value of C1, which the program calculates from Table F.1.1 and Table F.1.2 of the DD ENV code, from the user specified values of CMM and CMN parameters.
C2:
This parameter allows the user to specify the C2 parameter, which is used in the equation of the calculation of the Elastic Critical Buckling Moment, Mcr –which has been referred to in clause 6.3.2.2 of the EN 1993-1-1:2005 code. This equation can be seen in Annex F of the DD ENV code. This parameter would allow the user to overwrite the value of C2, which the program calculates from Table F.1.1 and Table F.1.2 of the DD ENV code, from the user specified values of CMM and CMN parameters.
C3:
This parameter allows the user to specify the C3 parameter, which is used in the equation of the calculation of the Elastic Critical Buckling Moment, Mcr –which has been referred to in clause 6.3.2.2 of the EN 1993-1-1:2005 code. This equation can be seen in Annex F of the DD ENV code. This parameter would allow the user to overwrite the value of C3, which the program calculates from Table F.1.1 and Table F.1.2 of the DD ENV code, from the user specified values of CMM and CMN parameters.
CMM:
This parameter allows the user to specify the load type and support conditions, as in Table F.1.1 and Table F.1.2 of Annex F of the DD ENV version of the EC3 code. The loading and the support conditions are one of the requirements to calculate the values of factors C1, C2 and C3 from tables F.1.1 and F.1.2 of Annex F of the DD ENV version of the EC3 code.
The CMM parameter values ranges from 1 to 8. The details of the values of these parameters are given in table 5B.2 of section 5B.6(B) of the International Code manual and reproduced below.
CMN:
This parameter is used to specify the end restraints, as in Table F.1.1 and Table F.1.2 of Annex F of the DD ENV version of the EC3 code. The end restraint condition is another requirement to calculate the values of factors C1, C2 and C3 from tables F.1.1 and F.1.2 of Annex F of the DD ENV version of the EC3 code.
There are three values of this parameter as described below:
1.0 = No fixity
0.5 = Full fixity
0.7 = One end free and other end fixed
The default value of this parameter is 1.0.
FU:
This parameter helps to specify the Ultimate Tensile Strength of Steel as per Table 3.1 of EN 1993-1-1-2005. This will overwrite the value of fu calculated by the program from the specification of the SGR parameter.
GM0:
This parameter allows the user to specify the value of γM0, as specified in clauses 2.4.3 and 6.1 of the EN 1993-1-1:2005 code.
The default value of this parameter is 1, as has been recommended for buildings in Note 2B of clause 6.1.
GM1:
This parameter allows the user to specify the value of γM1, as specified in clauses 2.4.3 and 6.1 of the EN 1993-1-1:2005 code.
The default value of this parameter is 1, as has been recommended for buildings in Note 2B of clause 6.1.
GM2:
This parameter allows the user to specify the value of γM2, as specified in clauses 2.4.3 and 6.1 of the EN 1993-1-1:2005 code.
The default value of this parameter is 1.25, as has been recommended for buildings in Note 2B of clause 6.1.
KC:
This parameter allows the user to specify the correction factor, kc – as in clause 6.3.2.3(2) and table 6.6 of EN 1993-1-1:2005. This value of kc is used to calculate the modification factor f, which is used to calculate the value of XLT,mod as per equation 6.58 of EN 1993-1-1:2005.
If the value of KC is specified as 1, the program automatically calculates the value of kc from table 6.6 of EN 1993-1-1:2005.
KY/KZ:
These parameters allow the user to specify the K factors of buckling lengths, which are calculated as Ky*Ly for buckling about the Y axis and Kz*Lz for the bukling length about the Z axis.
The buckling lengths are required to calculate the value of Ncr_F, Ncr_T or Ncr_TF as per clause 6.3.1.3 and 6.3.1.4, which is used to calculate the reduction factor X as per clause 6.3.1.2, which is subsequently used to calculate the buckling resistance of the member as per clause 6.3.1.1.
LY/LZ:
These parameters allow the user to specify the length factors of buckling lengths, which are calculated as Ky*Ly for buckling about the Y axis and Kz*Lz for the bukling length about the Z axis.
The buckling lengths are required to calculate the value of Ncr_F, Ncr_T or Ncr_TF as per clause 6.3.1.3 and 6.3.1.4, which is used to calculate the reduction factor X as per clause 6.3.1.2, which is subsequently used to calculate the buckling resistance of the member as per clause 6.3.1.1.
NA:
This parameter helps the user to invoke the National Annexure of their choice. The National Annexure Chosen as the value specified is as below:
0 – No National Annexure is invoked. Only the raw code is used.
1- British NA is used.
2- Netherlands NA is used.
3- Norwegian NA is used.
4- French NA is used.
The default value used is 0.
NSF:
This parameter helps the user to specify the Net Section Factor for tension members with holes. The net sectional area will be calculated as the product of NSF and the gross cross sectional area. The net area is used in equations 6.7 and 6.8 of clause 6.2.3 of EN 1993-1-1:2005.
The default value of the NSF factor is 1.
PY:
This parameter allows the user to specify the design strength of steel as per table 3.1 of EN 1993-1-1:2005. This will overwrite the value taken by the program on specification of the SGR parameter.
SBLT:
This parameter allows the user to specify the section as rolled or built-up. This is required for the choice of the appropriate buckling curve, as in table 6.4 and 6.5 of sections 6.3.2.2 and 6.3.2.3 of the EN 1993-1-1:2005.
A value of 0 will mean a rolled section and which is the default value. A value of 1 will mean a built-up or a welded section.
SGR:
This parameter allows the user to set the steel grade. This helps the program to choose the value of fy and fu from Table 3.1 of the EN 1993-1-1:2005 code. The values chosen by the program can respectively be overwritten by the PY and the FU parameters.
The following are the values that can be assumed by the SGR parameter against the respective steel grades they represent and which has the default value of 0.
0.0 - indicates S 235 grade steel
1.0 - indicates S 275 grade steel
2.0 - indicates S 255 grade steel
3.0 - indicates S 420 grade steel
4.0 - indicates S 460 grade steel
UNF/UNL:
Both of these parameters represent the unrestrained length in lateral torsional buckling. While the UNF represent the factor of total length which is unrestrained – the maximum value of it can be 1, the UNL parameter actually represents the unrestrained length. This length is used in the equation to calculate Mcr, the elastic critical moment for lateral torsional buckling, which is used in clause 6.3.2.2 of EN 1993-1-1:2005 to calculate the reduction factor to lateral torsional buckling.
ZG:
This parameter allows the user to specify the distance of the loading from the shear centre. This is used in the equation to calculate the Elastic Critical Moment, Mcr – as per Annex F of the DD ENV code. This parameter can assume both positive and negative values. The default value is +depth/2.
CAN:
This parameter allows the deflection check for cantilever beam elements. By default, the program assumes the beam element being supported at both the ends and the deflection check is done based on the figure as shown in section 5.44 of the Technical Reference Manual. However, this will not work for cantilever. To specify that beam element is a cantilever, you need to specify 1 for the CAN parameter. The default value of the CAN parameter is 0 – which means that the beam element is supported at both the ends.
DFF:
This parameter is used to specify the deflection limit. DFF is the ratio of the length of deflection to the allowable deflection. That is the allowable deflection is the product of the specified DFF and the length of the member.
DJ1/DJ2:
This is used to specify the start and the end node of the deflection length. This is used, when a beam member is split into more than one finite elements and the deflection length is neded to be specified as the total length instead of the individual length of finite element.
For example as shown in the figure above, Beam numbers 1 (between node 1 and node 2), 2 (between node 2 and 3) and 3(between nodes 3 and 4) make up a complete beam. So,the deflection check of beam 2, for example, would need the whole length being considered for deflection. So, we need to specify DJ1 1, meaning the start of the deflection length is at node 1 and DJ2 4 – meaning the end node of the deflection length is node 4.
NSF:
This means the Net Section Factor. The default value of this parameter is 1. This is used to provide any reduction to the area of the tension members due to the presence of bolt or rivet holes. If 10% of the section area is to be deducted from the gross section, the NSF needs to be specified as 0.9.
ESTIFF:
This is a parameter that is required for the Dutch NA. This has been discussed in details in the Dutch NA help document.
LEG:
This parameter is used to calculate the L/i values of angles and double angled sections from the BS 5950 specifications – the end connection details required for this as specified in table 25 of BS 5950-1:2000 is specified using the LEG parameter. We feel that the EN 1993-1-1:2005 code has not mentioned specifically on how to deal with the end connections to calculate the value of slenderness.
MU:
This parameter is required for the French NA. This has been discussed in details in the French NA help document.