The default parameter values have been selected such that they are frequently used numbers for conventional design. Depending on the particular design requirements, some or all of these parameter values may be changed to exactly model the physical structure.

DFF, DJ1, and DJ2 Parameters

(Analytical members only) Deflection calculations are not applicable to PMEMBERs.

Compute Delta = $\sqrt{{(\mathtt{\text{DX2}}-\mathtt{\text{DX1}})}^2+{(\mathtt{\text{DY2}}-\mathtt{\text{DY1}})}^2+{(\mathtt{\text{DZ2}}-\mathtt{\text{DZ1}})}^2}$

Compute Length = distance between DJ1 & DJ2 or, between start node and end node, as the case may be.

• A straight line joining DJ1 and DJ2 is used as the reference line from which local deflections are measured.

  For example, refer to the figure below where a beam has been modeled using four joints and three members. The "Deflection Length" for all three members will be equal to the total length of the beam in this case. The parameters DJ1 and DJ2 should be used to model this situation. Thus, for all three members here, DJ1 should be 1 and DJ2 should be 4.

  

  PARAMETERS
  DFF 300. ALL
  DJ1 1 ALL
  DJ2 4 ALL

  D = Maximum local deflection for members 1, 2, and 3.

• If DJ1 and DJ2 are not used, "Deflection Length" will default to the member length and local deflections will be measured from original member line.
• It is important to note that unless a DFF value is specified, STAAD.Pro will not perform a deflection check. This is in accordance with the fact that there is no default value for DFF.

IST Parameter

IST parameter is used to specify the residual stress category referred in table 5.2 and 6.2.4.

If IST is specified, then that value is used. But if not specified then residual stress category automated from shape of the section according to Note 1 of table 5.2.

LHT Parameter

If the shear force is constant within the segment, longitudinal position of the load is assumed to be at the segment end.

If there is any variation of the shear force and the load is acting downward determined from shear force variation and load height parameter indicates the load is acting on top flange (flange at the positive local y axis) and restraints at the end of the segment is not FU (FRU) or PU (PRU), Kl is taken to be 1.4.

If there is any variation of the shear force and the load is acting upward determined from shear force variation and load height parameter indicates the load is acting on top flange (flange at the positive local y axis) and restraints at the end of the segment is not FU (FRU) or PU (PRU) Kl is taken to be 1.0 as the load acting at the top flange is contributing to stabilize against local torsional buckling.

SGR Parameter

NZS3404 defines the values of steel grades that are used as either normal steel or high grade steel. The following table explains the material values used when either option is specified for a particular shape:

If a value for the FYLD parameter has been specified, then that value will be used. Otherwise, the SGR value will be used to determine the yield strength and tensile strength values for the steel. based on maximum thickness of the individual elements of the section. Only for shear capacity calculation web thickness is used. Similarly, Tensile Strength is determined either from FU parameter or from SGR parameter.

A check is introduced to see if yield stress is less than 100 MPa or more than 450 MPa or not. If less than 100 MPa, a warning is issued but the yield stress will not be modified. If more than 450 MPa, then also a warning is issued and the yield stress is set to 450 MPa.

PBRACE Parameter

PBRACE {TOP | BOTTOM} f1 r1 f2 r2 … f52 r52 (PMEMB pmember-list)

where:

PBCRES Parameter

PBCRES {ZZ | YY} f1 r1 f2 r2 … f52 r52 (PMEMB pmember-list)

where: