Method of fundamental solution and genetic algorithms for torsion of bars with multiply connected cross sections

The torsion of bars with a multiply connected cross sections by means of the method of fundamental solutions (MFS) is considered herein. To determine the optimal parameters of MFS, genetic algorithms were used. Seven cases of cross sections are considered. The numerical results for different cross sectional shapes are presented to demonstrate the efficiency and accuracy of the method. Non-dimension torsional stiffness was calculated by means of numerical integration of the stress function for one of the cases. This stiffness is compared with the exact stiffness for the first case and with the stiffness resulting from Bredt's formulae for thin walled cross sections.