How does one categorize a structural element and designate it accordingly with the proper STAAD entity?
There are 3 choices when it comes to modeling structural entities. They are : frame members, plate elements and solid elements.
As a general thumb rule, if in a cuboid, the ratio of the largest dimension to the smallest dimension is less than 10, it is preferable to designate the element as a Solid.
For example , in the cuboid, if we call the largest dimension "L" , the second largest dimension as "B" and the smallest one as "T" like ( L>B>T) , there may be three conditions :
(1) If L/T <10 (then obviously B/T<10), then the element can be set to a solid.
(2) If L/T >10 but B/T <10 , then the element is more like a member than a solid or a plate element.
(3) If L/T >10 and B/T >10 , then the element is more like a plate element.