| Applies To | |||
| Product(s): | RAM Elements | ||
| Version(s): | All | ||
| Area: | Design; Analysis |
RAM Elements - Member Deflections
In RAM Elements, member deflections are calculated from the finite element results. Internally this is determined using end nodal rotations, along with member shear and moments. The program can report member deflection ratios (Deflection / Member Length) and even optimize this against user defined limits, but for this feature to be effective, physical members are suggested.
As noted in the figure, the local deflections are based on the member length, so when physical members are used the member length is logical. If the member (girder, truss chord, etc.) is segmented into shorter elements then this length, and the local member deflection ratio, becomes meaningless.
If your model is already segmented and you want to merge the segments into a physical member, select the members and the intermediate nodes (not the end nodes) and use the Ribbon menu tool - Segmentation - Merge Members (and keep nodes).
Note, member default unbraced length is also something that defaults to the member length. If segmented members are merged you may need to assign Lb pos, Lb neg, L22 and/or L33.
When optimizing member for defection, a "Service" type Load Combination is required (even if performing Allowable Stress Design.
For more see: Ram Elements Load Combos [FAQ]