| Applies To | |||
| Product(s): | RAM Structural System; Ram Frame | ||
| Version(s): | Any | ||
| Area: | Analysis | ||
Problem Description
Red status lights are shown to the left of wind and seismic load cases in RAM Frame - Process - Analyze. These load cases cannot be analyzed.
Reason
When wind and seismic load cases are defined to use the calculated frequency and period, the program is required to run an Eigen Analysis to find the fundamental frequency and period for each direction. If there is insufficient information to solve the Eigen Analysis, red status lights will be displayed on the left of the load case and you will not be able to include them in the analysis.
Two common reasons for the red status lights:
- All diaphragms in the model are defined as Flexible diaphragms.
- One or more diaphragms in the model has 0 mass (or very small values of mass and mass moment of inertia). Verify this in RAM Frame - Loads - Masses.
- There are no lateral members connected to any diaphragms in the model.
Steps to Resolve
Consider using one of the following to work around this issue:
- If all levels are Flexible, use nodal lateral loads modeled in RAM Modeler to account for the lateral loads. Program generated load cases do not apply to flexible diaphragms.
- Use a specified frequency and/or period instead of the calculated values. When this is done, an Eigen Analysis is no longer required.
- Make sure that each diaphragm has non-zero mass. Self-mass options are defined in RAM Manager - Criteria - Self-Weight. You can also use specified mass values in RAM Frame - Loads - Masses
See Also
[[Red Lights for Load Combinations in Ram Frame]]
Structural Product TechNotes And FAQs
[[Ram Frame - Masses]]