https://communities.bentley.com/products/ram-staad/f/ram-staad-forum/139151/ram-ss-v15-05-diaphragm-stiffness-modification-factorsThe newest version of RAM SS 15.05 now has unique stiffness modification factors for each deck direction for materials such as corrugated roof deck. However, I haven&#39;t found diagram, or example explaining what the factors &quot;f11&quot;, &quot;f22&quot;, &quot;f12&quot;, &quot;m11&quot;, en-USTelligent Community 12https://communities.bentley.com/thread/421477?ContentTypeID=1Mon, 31 Jul 2017 15:19:19 GMT6dad98f5-dbc9-4c4d-a9ba-e9da8dc6aa8e:39bdfb87-8c2e-452d-8aa6-7ea847d3edf1Seth Guthrie<p>The RamFrameAnalysis.pdf manual has details on these factors. I&#39;ve included section 6.24 from the version 15.05 manual below, but the formatting is better in the original pdf.&nbsp;</p> <p>Allen Adams will be presenting another webinar on &quot;Diaphragm&nbsp;Design in Modern Structures&quot; in the fall, so watch the RAM News Feed or our <a href="/products/ram-staad/f/ram-staad-announcements-forum#pi25818=1">Announcements Forum</a> for details about that. Here&#39;s a <a href="/products/ram-staad/w/structural_analysis_and_design__wiki/22571/bentley-success-factors-webinar-a-practical-approach-to-using-the-response-spectra-analysis-method">link</a> to the Q&amp;A from his last one.&nbsp;</p> <p><a href="/cfs-file/__key/communityserver-discussions-components-files/5932/pastedimage1501513912656v1.png"><img src="/resized-image/__size/700x600/__key/communityserver-discussions-components-files/5932/pastedimage1501513912656v1.png" alt=" " /></a></p> <p></p> <p><a href="/cfs-file/__key/communityserver-discussions-components-files/5932/pastedimage1501513999222v2.png"><img src="/resized-image/__size/800x600/__key/communityserver-discussions-components-files/5932/pastedimage1501513999222v2.png" alt=" " /></a></p> <p><a href="/cfs-file/__key/communityserver-discussions-components-files/5932/pastedimage1501514127906v3.png"><img src="/resized-image/__size/700x600/__key/communityserver-discussions-components-files/5932/pastedimage1501514127906v3.png" alt=" " /></a></p><div style="clear:both;"></div>