RAM Structural System Help

Drift Control - Results

The Process - Results command allows the user to visually observe, through normalized color-coding, the contribution of each member to overall building flexibility. These quantities are called "Displacement Participation Factors" [DPF] or alternatively PF, for short. The following DPF are available for color-coded display:

  • Total Displacement Participation Factor - This represents the total member contribution (which is the sum of axial, shear, flexure, torsion and joint displacements) and is the default used in the module whenever Drift Control analysis is carried out.
  • Total Displacement/Volume Participation Factor - The total DPF divided by the member volume gives critical information for a minimum weight (or volume) design. Information on Total DPF per volume helps identify members whose size can be modified to arrive at the most weight/volume optimized design. Total DPF/Volume is also called the Sensitivity Index (SI). SI can also be viewed as a measure of the participation of each member per unit volume.
  • Axial Displacement Participation Factor - This represents the contribution of members through axial deflection.
  • Shear Displacement Participation Factor - This represents the contribution of members through major and minor shear deflection.
  • Flexural Displacement Participation Factor - This represents the contribution of members through major and minor flexural deflection.
  • Joint Displacement Participation Factor - This represents the contribution of members through deflections in the rigid end zone. In centerline analysis, the joint DPFs are all zero.
  • Member Volume - This represents the volume of the member under consideration.

The currently selected load pair can be changed through the "load pair" drop-down box. The quantities of interest can also be changed through the drop-down box that lists all displacement participation quantities and member volume.