Stress Analysis of Closed Multi Cell Sections under Torsion

Closed multi cell sections under torsion are used as structural members to investigate how the shear stresses vary over the cross section and to find the magnitude and location of the maximum stress. The boundary of cells in one type of sections, are circles. Sections with different geometrical ratios are considered. The shear stress is calculated by finite element method, and the results are plotted. The maximum of these stresses are determined and classified according to the area and polar moment of inertia ratios and plotted in separate diagrams to simplify interpolation. Rectangular boxes with the same and different wall thickness are also investigated as another type of closed multi cell sections. Stresses along the inner and outer edges near the corners and the mean shear stress along the middle line of all section walls are determined. Diagrams show considerable increase in the magnitude of stresses. Some findings are compared with similar quantities found in other references and differences are discussed.