MIL-HDBK-17-3F Volume 3.Chapter 1 General Information ax laminate coefficient of thermal expansion along general reference x axis(m/m/C, in/in/F) y laminate coefficient of thermal expansion along general reference y axis(m/m/C, in/in/F) d xy laminate shear distortion coefficient of thermal expansion(m/m/C.in/in/F) -angular orientation of a lamina in a laminate,i.e.,angle between 1 and x axes() Axy -product of vxy and vyx V12 Poisson's ratio relating contraction in the 2 direction as a result of extension in the 1 direction V21 -Poisson's ratio relating contraction in the 1 direction as a result of extension in the 2 direction Vxy Poisson's ratio relating contraction in the y direction as a result of extension in the x direction Vyx Poisson's ratio relating contraction in the x direction as a result of extension in the y direction Pe -density of a single lamina(kg/m3,Ib/in3) Pe density of a laminate (kg/m3,lb/in -(1)general angular coordinate,( -(2)angle between x and load axes in off-axis loading ( 1.3.1.3 Subscripts The following subscript notations are considered standard in MIL-HDBK-17. 1,2,3 -laminae natural orthogonal coordinates(1 is filament or warp direction) A axial -(1)adhesive -(2)alternating app -apparent byp -bypass c composite system,specific filament/matrix composition.Composite as a whole,contrasted to individual constituents.Also,sandwich core when used in conjunction with prime ( -(4)critical CA centrifugal force e fatigue or endurance eff effective eq -equivalent filament 8 glass scrim cloth H -hoop i -ith position in a sequence L lateral m -(1)matrix -(2)mean max maximum min minimum -(1)nih(last)position in a sequence -(2)normal p -polar symmetric st stiffener T transverse iThe convention for Poisson's ratio should be checked before comparing different sources as different conventions are used. 1-9MIL-HDBK-17-3F Volume 3, Chapter 1 General Information 1-9 α x - laminate coefficient of thermal expansion along general reference x axis (m/m/°C, in/in/°F) α y - laminate coefficient of thermal expansion along general reference y axis (m/m/°C, in/in/°F) α xy - laminate shear distortion coefficient of thermal expansion (m/m/°C,in/in/°F) θ - angular orientation of a lamina in a laminate, i.e., angle between 1 and x axes (°) λ xy - product of ν xy and ν yx ν 12 - Poisson's ratio relating contraction in the 2 direction as a result of extension in the 1 direction1 ν 21 - Poisson's ratio relating contraction in the 1 direction as a result of extension in the 2 direction1 ν xy - Poisson's ratio relating contraction in the y direction as a result of extension in the x direction1 ν yx - Poisson's ratio relating contraction in the x direction as a result of extension in the y direction1 ρ c - density of a single lamina (kg/m3 ,lb/in3 ) c ρ - density of a laminate (kg/m3 ,lb/in3 ) φ - (1) general angular coordinate, (°) - (2) angle between x and load axes in off-axis loading (°) 1.3.1.3 Subscripts The following subscript notations are considered standard in MIL-HDBK-17. 1, 2, 3 - laminae natural orthogonal coordinates (1 is filament or warp direction) A - axial a - (1) adhesive - (2) alternating app - apparent byp - bypass c - composite system, specific filament/matrix composition. Composite as a whole, contrasted to individual constituents. Also, sandwich core when used in conjunction with prime (') - (4) critical cf - centrifugal force e - fatigue or endurance eff - effective eq - equivalent f - filament g - glass scrim cloth H - hoop i - i th position in a sequence L - lateral m - (1) matrix - (2) mean max - maximum min - minimum n - (1) nth (last) position in a sequence - (2) normal p - polar s - symmetric st - stiffener T - transverse 1 The convention for Poisson’s ratio should be checked before comparing different sources as different conventions are used