296 FLOORS 



Corrugated flooring or trough plates are usually very hard to get 

 and the Z-bar and plate floor shown in (c) Fig. 145, and the angle and 



Pencoyd Corrugated Flooring Z Bar Floor Angle and Plate Floor 



(a) ( b) (c) (d } 



FIG. 145. 



plate floor shown in (d) are substituted. The details, weights and safe 

 loads for Z-bar and plate flooring are given in the handbooks above 

 -named. Angle and plate flooring is made of equal legged angles and 

 plates, and the safe loads are not given in the handbooks but must be 

 calculated. The moment of inertia, I, of a section of flooring contain- 

 ing two angles and two plates is given by the formula 



/ = 2/' + 2Ad 2 + 2!" 



where /' = moment of inertia of one angle about an axis through the 

 center of gravity of the angle parallel to the neutral axis of the flooring ; 

 A = area of one angle ; 



d = distance from center of gravity of the angle to the neutral 

 axis of the flooring ; 



/" moment of inertia of the plate about the neutral axis. 



The properties of the angles required in the calculations may be 

 obtained from the handbooks, and /" is equal to one-half the sum of the 

 moments of inertia of the plate about its long and its short diameter 

 since the sum of the moments of inertia about any pair of rectangular 

 axes is a constant. 



Buckled Plates. Buckled plates are made from soft steel plates 

 from 3 to 5 feet wide, and are from Y^ to 7-16 inches thick. Buckled 

 plates are made in lengths having from one to 15 buckles or domes in 

 one plate. Buckles vary in depth from 2 to 3^2 inches, however, dif- 

 ferent depths should not be used in the same plate. Buckled plates are 

 usually supported along the edges and the ends and are bolted to the 

 floor beams. The details, weights and safe loads are given in the hand- 

 books named above and in the Passaic Steel Company's handbook. The 



