6-78 DESIGN OF LAMINATES 



The minimum resisting moment of the section is: 

 Mjnin = 25,330 in- lbs. 



The ultimate uniform load for the minimum resisting moment and simply supported beam 

 from equation 6. 42 is: 



P 2fes .. 8 x 25,33 . 88 .o lbs . per in . 



L 2 U8 2 



The ultimate vertical shear that the composite section will resist due to the ultimate 

 horizontal shear at the neutral axis and at the secondary bond at the interface between the 

 stiffener and plate is obtained from equation 6.43. 



For ultimate shear at ne\itral axis* 



Q' = U. 296 x 0.1ii8 x 1.527 + 2 x 1.1^3 x 0.U8 x hMH 

 1 2 



= 1.283 in 3 



Ultimate parallel shear stress for woven roving, F s = 9,300 psi 



9,300 x 2.566 x 0.11+8 x 2 x 2.06 x 10 ^ = $ e, 10 lbs# 

 1 " 1.283 2.06 x 106 



For ultimate shear of secondary bond at interface of stiffener and plate: 



Q« = U.296 x 0.1U8 x 2.07h + 2 x 1.852 x 0.1U8 x 1.07U + 2 x 2.000 x 0.1ij8 x 0.07U 

 = 1.952 in3 



Ultimate secondary bond shear stress, F Bs = 1,000 psi 



1,000 x 2.566 x 2 x 2.000 2.06 x 10 6 _, n£n ,. 



V- = x - 7 = 5,260 lbs. 



2 1.952 2.06 x 10 6 



The minimum shear strength of the section is: 



v min = 5,260 lbs. 



The ultimate uniform load for the minimum shear and simply supported composite sec- 

 tion is obtained from equation 6. 30a. 



p = 2 x ^ 26 ° = 219.2 lbs. per in. 

 u U8 



The ultimate flexural stress controls and the ultimate carrying capacity of the composite 

 section is 88.0 lbs. per in. 



The maximum deflection of the simply supported uniformly loaded beam, including the 

 effect of shear is obtained from equation 6. 28). 



