... - v120,) E22 1 e, = - 6, G (2 -42 ) (2 -43 ) (2 -44 ) (2 -45 ) (2 -46 ) Substituting Eq. 2-35, 2-36, and 2-37 into 2 -44 , 2 -45 , and 2 -46 results in, e, = - (cos2 6- v12 sin2 ... = E22 1 e, = - (sin @cos 6)ol G (2 -47 ) (2 -48 ) (2 -49 ) Finally, substituting Eqs. 2 -47 , 2 -48 , and 2 -49 and 2 -41 , 2 -42 , and 2 -43 into Eqs. 2-29,2-30, and 2-31, and after ... sectional area 4. For shear modulus G the equation becomes: i=n GA = C GjA; (2-23) i=l 128 Plastics Engineered Product Design and since A, = 1 Sf 1 -= Af+k(l -Ad 4 (2- 74) (2-75)...