A hybrid formulation in the stress analysis of curved pipes

Describes a hybrid formulation solution based on variational techniques, wh ere unknown functions are combined with a set of Fourier trigonometric expa nsions. The unknown functions refer to the toroidal shell distortion in the longitudinal direction when the shell is submitted to generalised in-plane forces in the linear-elastic stress field. This set of functions is solved from a system of differential equations, having calculated the eigenvalues and corresponding eigenvectors in the complex field from the system equati ons matrix. For this purpose the MAPLE(R) mathematical solver was used. Thi s module led to an analytical solution, which is exact for each Fourier ter m used in the global solution. The final results agree very well with finit e element method or other solutions obtained using a total expansion of tri gonometric functions in the longitudinal and meridional directions.