Secondary torsion moment deformation effect (STMDE) by Boundary Element Method in composite bars with variable cross sections

Resumo

This paper proposes a formulation for solving torsion problems in composite bars with variable cross

sections including secondary torsion moment deformation effect (STMDE). The Boundary Element Subregion-
by-Subregion (BE-SBS) Technique is applied to model cross sections with general shape and constituted of any

number of different materials. Four boundary value problems are solved. The primary and secondary warping
functions are determined by applying the Boundary Element Method, while the primary and secondary twist
angles, θ pand θs, along the element axis are solved by a process based on the weighted residual method. It is
worth mentioning that iterative Krylov’s solvers are used, which results in saving memory and solver time. The
efficiency, robustness and accuracy of the implemented algorithm are demonstrated in several numerical
examples.