Page Comparison

h2. How do I run a pseudo-static lateral analysis?

*Extended Question:* I need to run a pseudo-static lateral analysis in which structural inertia represents the earthquake load. I would like to apply a seismic coefficient to inertia such that lateral force is a fraction of g, and not an acceleration function similar to [response spectra|kb:Response-spectrum analysis] or [time history|kb:Time-history analysis]. How is this done?

*Answer:* Pseudo-static seismic load may be assigned by applying a gravity load in the lateral direction. This is done as follows:

# Define a separate [load pattern|kb:Load pattern], perhaps named Inertia.
\\
\\
# Select Assign > Frame Loads _or_ Area Loads _or_ Solid Loads > Gravity, then assign the load pattern with gravity multipliers in the Global X or Y direction.
\\
\\
# Specify a self-weight multiplier of 0 such that the self-weight of the structure is not included in the [load case|kb:Load case]. You may always check base reactions in the output tables for a given case or combination to ensure that self-weight is applied correctly.

\\

An alternative is to use the seismic [auto lateral load|kb:Auto lateral load] pattern to calculate and assign the load according to specific requirements. This procedure is documented in the Lateral Loads Manual, available in the Manuals directory of the software installation directory. 

{hidden-content}
*Related Incident:*
* {incident:no=48096|comment=How to Define Inertia Load}
{hidden-content}