DA11_R intop1(-shell.RFx/d) "Equivalent extensional stiffness matrix, 11-component" DA12_R intop1(-shell.RFx/d) "Equivalent extensional stiffness matrix, 12-component" DA21_R intop2(-shell.RFy/(2*c)) "Equivalent extensional stiffness matrix, 21-component" DA22_R intop2(-shell.RFy/(2*c)) "Equivalent extensional stiffness matrix, 22-component" DA33_R intop1(-shell.RFy/d) "Equivalent extensional stiffness matrix, 33-component" DD11_R intop1(shell.RMy/d)*L "Equivalent bending stiffness matrix, 11-component" DD12_R intop1(shell.RMy/d)*L "Equivalent bending stiffness matrix, 12-component" DD21_R intop2(-shell.RMx/(2*c))*L "Equivalent bending stiffness matrix, 21-component" DD22_R intop2(-shell.RMx/(2*c))*L "Equivalent bending stiffness matrix, 22-component" DD33_R 0.5*(intop1(shell.RMx/(d))+intop2(-shell.RMy/(2*c)))*L "Equivalent bending stiffness matrix, 33-component"