6-44 



DESIGN OF LAMINATES 



Radius of Gyration, r «V y 



1.73 in. 



xx 



yy 



V 3.0 



= /^?625 „ oM in . 



ITo 



Maximum - = — J? .. = IOI4 

 r 



Tnm 



From Fig. 6-25 F cr = 850 psi 



P cr = A F cr = 3.0 x 850 = 2550 lbs. 



(6. 19) 



DESIGN EXAMPLE 6-16. COMPRESSION IN WOVEN ROVING LAMINATE 



A simply supported woven roving laminate 36 in. long and 12 in. wide is to support a 

 compressive load of 7, 500 lbs. in the warp direction. What must its thickness be for a 

 factor of safety of 2 on the ultimate compressive stress? See Fig. 6-29. 



7500 LBS 



-i 1 - 



Fig. 6-29. Woven Roving Laminate 

 in Compression 



Area = 12 x t 



12 t 3 ~ 

 iMin - Ixx = "jj- = V 



