A MODIFIED FOURIER-SERIES METHOD FOR THE TORSION ANALYSIS OF BARS WITH MULTIPLY CONNECTED CROSS-SECTIONS

A modified Fourier series method is proposed for the torsion analysis of prismatic bars with multiply connected cross sections. The kev feat ure in the present approach is the combined use of polynomials and Fou rier series solutions unlike in the existing approaches which use the Fourier series only. The replacement of the zeroth harmonic terms in t he Fourier series solutions by carefully selected polynomials resolves the major problem of functional dependence which the direct Fourier s eries method may pose. The polynomials and Fourier series solutions ar e selected to satisfy the governing equation exactly so that the numer ical calculation is minimal. The effectiveness and generality of the p resent method is verified through numerical examples. (C) 1997 Elsevie r Science Ltd.