MIL-HDBK-17-3F Volume 3,Chapter 1 General Information a-coefficient of thermal expansion of impregnated glass scrim cloth in the filament direction or in the warp direction of a fabric(m/m/C,in/in/F) a-coefficient of thermal expansion of impregnated glass scrim cloth transverse to the filament di- rection or to the warp direction in a fabric(m/m/C,in/in/F) -Poisson's ratio of filament material vm -Poisson's ratio of matrix material v-glass scrim cloth Poisson's ratio relating to contraction in the transverse(or fill)direction as a result of extension in the longitudinal(or warp)direction -glass scrim cloth Poisson's ratio relating to contraction in the longitudinal(or warp)direction as a result of extension in the transverse (or fill)direction -applied axial stress at a point,as used in micromechanics analysis(MPa,ksi) 2 applied shear stress at a point,as used in micromechanics analysis(MPa,ksi) 1.3.1.2 Laminae and laminates The following symbols,abbreviations,and notations apply to composite laminae and laminates.At the present time the focus in MIL-HDBK-17 is on laminae properties.However,commonly used nomen- clature for both laminae and laminates are included here to avoid potential confusion. A(j=1,2,6) extensional rigidities (N/m,Ibf/in) B(i5=1,2,6) coupling matrix(N,Ibf) C(ij=1,2,6) elements of stiffness matrix(Pa,psi) D Dy flexural rigidities (N-m,Ibf-in) Dy -twisting rigidity (N-m,lbf-in) D(ij=1,2,6) flexural rigidities(N-m,Ibf-in) E -Young's modulus of lamina parallel to filament or warp direction(GPa,Msi) E2 -Young's modulus of lamina transverse to filament or warp direction(GPa,Msi) -Young's modulus of laminate along x reference axis(GPa,Msi) E Young's modulus of laminate along y reference axis(GPa,Msi) G12 shear modulus of lamina in 12 plane(GPa,Msi) Gxq -shear modulus of laminate in xy reference plane(GPa,Msi) h -thickness of it ply or lamina(mm,in) M,My,Mxy bending and twisting moment components(N-m/m,in-lbf/inin plate and shell analy- sis) 名 number of filaments per unit length per lamina Q Qy shear force parallel to z axis of sections of a plate perpendicular to x and y axes,re- spectively (N/m,Ibf/in) Q(j=1,2,6) reduced stiffness matrix(Pa,psi) Ux,Uy,Uz components of the displacement vector(mm,in) u哏，u9,u2 -components of the displacement vector at the laminate's midsurface(mm,in) V void content(%by volume) Vr -filament content or fiber volume(%by volume) Ve glass scrim cloth content(%by volume) Vm matrix content (by volume) Vx,Vy edge or support shear force(N/m,Ibf/in) Wr filament content(%by weight) Wg glass scrim cloth content(%by weight) m matrix content(%by weight) Ws weight of laminate per unit surface area(N/m2,lbf/in) Q1 -lamina coefficient of thermal expansion along 1 axis(m/m/C,in/in/F) Q2 lamina coefficient of thermal expansion along 2 axis(m/m/C,in/in/F) 1-8MIL-HDBK-17-3F Volume 3, Chapter 1 General Information 1-8 x g α - coefficient of thermal expansion of impregnated glass scrim cloth in the filament direction or in the warp direction of a fabric (m/m/°C,in/in/°F) y g α - coefficient of thermal expansion of impregnated glass scrim cloth transverse to the filament di￾rection or to the warp direction in a fabric (m/m/°C,in/in/°F) νf - Poisson's ratio of filament material ν m - Poisson's ratio of matrix material xy g ν - glass scrim cloth Poisson's ratio relating to contraction in the transverse (or fill) direction as a result of extension in the longitudinal (or warp) direction yx g ν - glass scrim cloth Poisson's ratio relating to contraction in the longitudinal (or warp) direction as a result of extension in the transverse (or fill) direction σ - applied axial stress at a point, as used in micromechanics analysis (MPa,ksi) τ - applied shear stress at a point, as used in micromechanics analysis (MPa,ksi) 1.3.1.2 Laminae and laminates The following symbols, abbreviations, and notations apply to composite laminae and laminates. At the present time the focus in MIL-HDBK-17 is on laminae properties. However, commonly used nomen￾clature for both laminae and laminates are included here to avoid potential confusion. Aij (i,j = 1,2,6) - extensional rigidities (N/m,lbf/in) Bij (i,j = 1,2,6) - coupling matrix (N,lbf) Cij (i,j = 1,2,6) - elements of stiffness matrix (Pa,psi) Dx, Dy - flexural rigidities (N-m,lbf-in) Dxy - twisting rigidity (N-m,lbf-in) Dij (i,j = 1,2,6) - flexural rigidities (N-m,lbf-in) E1 - Young's modulus of lamina parallel to filament or warp direction (GPa,Msi) E2 - Young's modulus of lamina transverse to filament or warp direction (GPa,Msi) Ex - Young's modulus of laminate along x reference axis (GPa,Msi) Ey - Young's modulus of laminate along y reference axis (GPa,Msi) G12 - shear modulus of lamina in 12 plane (GPa,Msi) Gxy - shear modulus of laminate in xy reference plane (GPa,Msi) hi - thickness of i th ply or lamina (mm,in) Mx, My, Mxy - bending and twisting moment components (N-m/m, in-lbf/in in plate and shell analy￾sis) nf - number of filaments per unit length per lamina Qx, Qy - shear force parallel to z axis of sections of a plate perpendicular to x and y axes, re￾spectively (N/m,lbf/in) Qij (i,j = 1,2,6) - reduced stiffness matrix (Pa,psi) ux, uy, uz - components of the displacement vector (mm,in) x o y o z o u , u , u - components of the displacement vector at the laminate's midsurface (mm,in) Vv - void content (% by volume) Vf - filament content or fiber volume (% by volume) Vg - glass scrim cloth content (% by volume) Vm - matrix content (% by volume) Vx, Vy - edge or support shear force (N/m,lbf/in) Wf - filament content (% by weight) Wg - glass scrim cloth content (% by weight) Wm - matrix content (% by weight) Ws - weight of laminate per unit surface area (N/m2 ,lbf/in2 ) α 1 - lamina coefficient of thermal expansion along 1 axis (m/m/°C,in/in/°F) α 2 - lamina coefficient of thermal expansion along 2 axis (m/m/°C,in/in/°F)