NOTATION x,y,a Rectangular coordinates r,Polar coordinates ra,ry Radii of curvature of the middle surface of a plate in xz and yz planes, respectively h Thickness of a plate or a shell g Intensity of a continuously distributed load p Pressure P Single load Weight per unit volume ,Normal components of stress parallel to y,and z axes Normal component of stress parallel to n direction Ur Radial stress in polar coordinates ,o Tangential stress in polar coordinates Shearing stress Tav:Tan Tuz Shearing stress components in rectangular coordinates u,v,w Components of displacements eUnit elongation Unit elongations in z,y,and z directions Er Radial unit elongation in polar coordinates a,se Tangential unit elongation in polar coordinates Unit elongations of a shell in meridional direction and in the direetion of parallel circle,respectively Y,Y,Yy Shearing strain components in rectangular coordinates r Shearing strain in polar coordinates E Modulus of elasticity in tension and compression G Modulus of elasticity in shear y Poisson's ratio V Strain energy D Flexural rigidity of a plate.or shell M,M Bending moments per unit length of sections of a plate perpendicular to x and y axes,respectively M Twisting moment per unit length of section of a plate perpendicular to x axis Ma,M Bending and twisting moments per unit length of a section of a plate perpendicular to n direction Q,Q Shearing forces parallel to z axis per unit length of sections of a plate perpendicular to x and y axes,respectively Q Shearing force parallel to a axis per unit length of section of a plate perpendicular to n direction Na,N Normal forces per unit length of sections of a plate perpendicular to x and y directions,respectively xiiiNOTATION x, y, z Rectangular coordinates r, 0 Polar coordinates rx, ry Radii of curvature of the middle surface of a plate in xz and yz planes, respectively h Thickness of a plate or a shell q Intensity of a continuously distributed load p Pressure P Single load 7 Weight per unit volume (Tx, <rV) (Tt Normal components of stress parallel to x, y, and z axes (Tn Normal component of stress parallel to n direction o> Radial stress in polar coordinates at, (re Tangential stress in polar coordinates r Shearing stress Txy, Txz, Tyz Shearing stress components in rectangular coordinates u, v, w Components of displacements e Unit elongation «*, «•/, fz Unit elongations in x, y, and z directions er Radial unit elongation in polar coordinates et , eo Tangential unit elongation in polar coordinates ttp, eo Unit elongations of a shell in meridional direction and in the direction of parallel circle, respectively yxy, Vxz, jyz Shearing strain components in rectangular coordinates 7r0 Shearing strain in polar coordinates E Modulus of elasticity in tension and compression G Modulus of elasticity in shear v Poisson's ratio V Strain energy D Flexural rigidity of a plate or shell Mx, My Bending moments per unit length of sections of a plate perpendicular to x and y axes, respectively Mxy Twisting moment per unit length of section of a plate perpendicular to x axis Mn, Mnt Bending and twisting moments per unit length of a section of a plate perpendicular to n direction Qx, Qy Shearing forces parallel to z axis per unit length of sections of a plate perpendicular to x and y axes, respectively Qn Shearing force parallel to z axis per unit length of section of a plate perpendicular to n direction JVx, Ny Normal forces per Unit length of sections of a plate perpendicular to x and y directions, respectively