https://communities.bentley.com/communities/other_communities/chinafirst/w/chinawiki/43784/cmen-USTelligent Community 12https://communities.bentley.com/communities/other_communities/chinafirst/w/chinawiki/43784/cmWed, 16 Oct 2019 03:33:45 GMT6dad98f5-dbc9-4c4d-a9ba-e9da8dc6aa8e:12ccd6aa-6402-41b5-b7e4-21d5e31a5dadQiang Hehttps://communities.bentley.com/communities/other_communities/chinafirst/w/chinawiki/43784/cm#commentsCurrent Revision posted to 技术资料库 by Qiang He on 10/16/2019 3:33:45 AM<br /> <p><span>Cm</span>系数考虑的是由于<span>P-&delta;</span>效应（假定杆件端部无横向位移）导致的弯矩放大作用。关于<span>CM</span>的取值在<span>POST 3.3.5.4</span>节中提到了杆件分类（<span>member class</span>）：包含主次结构（<span>primary , secondary</span>）<span>.</span>在<span>AISC</span>规范中对于屋架有主次结构杆件的分类，<span>SACS</span>中主次结构的分类就是其字面的意思，如果需要，需要由用户自己设定主次结构，并且<span>SACS</span>中的主次结构分类仅仅只是标记的作用，对计算没有影响，对计算有影响的是<span>CM</span>的取值。</p> <p><img src="/resized-image/__size/640x480/__key/communityserver-wikis-components-files/00-00-00-04-10/pastedimage1571196861335v1.png" alt=" " /></p> <p><span>SACS</span>中对<span>CM</span>的取值按主次结构成对给出选项设置，是为了方便用户自己进行设定分类。</p><div style="clear:both;"></div>