DESIGN OF A FLOORBEAM. 



.V.M 



Rivt t holes arc considered as spaced 3 in. along the section A-A, for when the beam is detailed 

 ii i-, not probable that they will be spaced closer than 3 in. Holes are deducted from the tension 

 side only. I in. holes being deducted for % in. rivets. 



The plates may not be exactly as indicated on Fig. 13 for it may be necessary to alter them 

 slightly in detailing, but small changes will not change the results materially. It is quite an 

 a<l\. mtage to have the investigation made before the beam is completely detailed as alterations 

 are more easily made at that time if the beam proves weak in any particular. 



The curved angle at the bottom will not be considered as adding to the strength. 



Values for the area, eccentricity and moment of inertia are found as follows. 



First the moments and moments of inertia of the separate parts are found about an axis 

 through the geometric center of the section, the eccentricity is then calculated. The moment 

 of inertia about an axis through the center of gravity is found by subtracting the product of the 



FIG. 13. DETAIL OF FLOORBEAM CONNECTION. 



area and the eccentricity squared from the moment of inertia about the axis through the geometric 

 center or 



J J - A .iA 

 *C * 1 r 



Note. For sake of simplicity the total section was divided up as follows: 



A, includes three 1 A in. and two % in. plates, the 6" X %" legs of the flange angles and % 

 in. -\-% in. of the 4" X Y*" leg. The spaces allowed for clearance were considered as solid with 

 no appreciable error. 



B, includes the remainder of the 4" X %" legs of flange angles. 



C, includes the % in. outside plates considered as solid. 



D, includes the rivet holes, i in. in diameter and 3.5 in. long, spaced 3 in. center to center. 



