3 *2 3D VIEW TOP VIEW () ↑3 2 2 61 3D VIEW 6) TOP VIEW 13 12 2 2 T12 F12 -12 T12 3D VIEW ( TOP VIEW FIGURE 2.2 Illustration of deformations of an orthotropic material due to (a)stress o,(b)stress o2,and(c) stress t2. V21=V12E2/E (2.8) The in-plane shear modulus,G2,is defined as(Figure 2.2c) G12=t12/M12 (2.9) It is often convenient to express stresses as functions of strains.This is accomplished by inversion of Equation(2.4) 1 Qi Q12 0 E1 Q12 Q22 0 (2.10) 0 0 Q66 Y12 ©2003 by CRC Press LLCν21 = ν12E2/E1 (2.8) The in-plane shear modulus, G12, is defined as (Figure 2.2c) G12 = τ12/γ12 (2.9) It is often convenient to express stresses as functions of strains. This is accomplished by inversion of Equation (2.4) (2.10) FIGURE 2.2 Illustration of deformations of an orthotropic material due to (a) stress σ1, (b) stress σ2, and (c) stress τ12. 1 2 12 11 12 12 22 66 1 2 12 = Q Q Q Q Q σ σ τ ε ε γ                                   0 0 0 0 TX001_ch02_Frame Page 13 Saturday, September 21, 2002 4:48 AM © 2003 by CRC Press LLC