Missing Load Cases from Generated RAM Frame Load Combinations


 Product(s):RAM Structural System
 Version(s):Any
 Environment: N/A
 Area: Analysis
 Original Author:Bentley Technical Support Group

Problem Description

Some wind and/or seismic load cases have been analyzed in RAM Frame but are not included in any of the generated load combinations.

Reason

This is typically associated with the option selected for Notional Loads in the load combination dialog:

In most cases, the wind and seismic lateral loads have been defined with the box for "Generate Additional Load Cases for Analysis with Tension-Only Members" checked. This creates positive and negative lateral load cases in the x and y directions. However, the notional load case has been defined without the same option checked.  This creates only positive notional load cases; negative notional load cases are not generated.

If "Consider with all combination in direction of lateral load" is selected for Notional Loads in the load combination dialog, the program recognizes that there are negative wind and/or seismic load cases but no negative notional load cases. Currently, the RAM Structural System load combination generator will generate a combination if all of the load cases in the combination are available, but will not generate the combination if any of the load cases in the combination are not available. Because there are negative wind and/or seismic load cases but no negative notional load cases, no combinations containing the negative lateral load cases are generated.

Steps to Resolve

Change the Notional Load Case and check the box for "Generate Additional Load Cases for Analysis with Tension-Only Members."