xviii Notation Quantity Symbol SI Unit Deviatoric stress G N/m2 Deviatoric strain E' Hydrostatic or mean stress 0 N/m2 Volumetric strain △ Stress concentration factor K Strain energy U J Displacement 6 m Deflection 6 or y m Radius of curvature P m Photoelastic material fringe value f N/m2/fringe/m Number of fringes n Body force stress X,Y,Z N/m3 Fg:Fo,Fz Radius of gyration m Slenderness ratio L/k Gravitational acceleration 9 m/s2 Cartesian coordinates x,y,2 Cylindrical coordinates r,0,z Eccentricity e m Number of coils or leaves of spring n Equivalent J or effective polar moment of area JE m Autofrettage pressure P N/m2 or bar Radius of elastic-plastic interface m Thick cylinder radius ratio R2/R K Ratio elastic-plastic interface radius to internal radius of thick cylinder R/R Resultant stress on oblique plane Pn N/m2 Normal stress on oblique plane On N/m2 Shear stress on oblique plane Tn N/m2 Direction cosines of plane 1,m,n Direction cosines of line of action of resultant stress ,m,n' Direction cosines of line of action of shear stress ls,ms,ns 一 Components of resultant stress on oblique plane Pxn>Pyn,Pan N/m2 Shear stress in any direction o on oblique plane N/m2 Invariants of stress N/m2 (N/m2)2 N/m2)3 Invariants of reduced stresses 1,J2,J3 Airy stress functionxviii Notation Quantity Symbol Deviatoric stress Deviatoric strain Hydrostatic or mean stress Volumetric strain Stress concentration factor Strain energy Displacement Deflection Radius of curvature Photoelastic material fringe value Number of fringes Body force stress Radius of gyration Slenderness ratio Gravitational acceleration Cartesian coordinates Cylindrical coordinates Eccentricity Number of coils or leaves of spring Equivalent J or effective polar moment of area Autofrettage pressure PA Radius of elastic-plastic interface RP Thick cylinder radius ratio R2/R1 K m Ratio elastic-plastic interface radius to internal radius of thick cylinder R,/R1 Resultant stress on oblique plane Normal stress on oblique plane Shear stress on oblique plane Direction cosines of plane Direction cosines of line of action of resultant stress Direction cosines of line of action of shear stress Components of resultant stress on oblique plane Shear stress in any direction 4 on oblique plane Invariants of stress Invariants of reduced stresses Airy stress function SI Unit N/m2 N/mz - - - J m m m N/m2/fringe/m N/m3 - m4 N/m2 or bar m - N/m2 N/m2 N/m2 - N/m2