DESIGN OF LAMINATES 



6-23 



Dl RECTI ON OF WARP 

 FOR ALL PL I ES 



1/1 6" 



CLOTH 



MAT 



CLOTH 



,-1/16" 



1/." 



Fig. 6-19. Composite Laminate Under 

 Tensile Load 



(6. 13) 



PL 

 e = — 



AE 



where e = total elongation, in. 

 P = load, lbs. 

 L = length, in. 

 A = area, sq. in. 



E = modulus of elasticity in tension, psi 



For two laminae of identical length and area, and subjected to the same load P, 

 equation 6. 13 indicates that the elongation of each lamina will then be proportional to E^ 

 the modulus of elasticity in tension. 



DESIGN EXAMPLE 6-8. ELONGATION OF VARIOUS TYPES OF LAMINATES 



Find the total elongation, e, for the laminates shown in Fig. 6-20. The laminates are 

 loaded parallel to the warp direction. 



2 OZ MAT 



-A = 5 Sq I N. 



^T 



50000 LBS 



1 0Z CLOTH 



A = 5 SQ IN. 



50000 LBS 

 b 



WOVEN ROVI NG 



. A = 5 SQ IN. 



Fig. 6-20. Elongation of Various Laminates 



