Elastic plane frame analysis of semisymmetric cabs and canopies used on underground electric face equipment. Report of investigations

The report presents a method based on plane frame theory by which certain types of protective cabs and canopies used on underground electric face equipment can be analyzed elastically. To be amenable to analysis by this method cabs and canopies must contain symmetry about one plane. Additionally, protective structures with one or more top members in the long direction that do not frame into the columns should be twice as long as they are wide and have two or more internal top members in the short direction. The assumptions and limitations of the plane frame method as regards analysis of three dimensional cabs and canopies are discussed. A step by step procedure for application of the plane frame method is given and three calculated for the three example canopies compare within 10% of those computedby the more complicated space frame analysis. Formulas employed in plane analysis of cabs and canopies are given in appendices. (Modified author abstract) (GRA)