FREE TORSION OF THIN-WALLED COMPOSITE RODS

Thin-walled composite rods, which have high specific rigidity and strength, find ever more widespread application as drive shafts, torsion rods, and other structural elements operating under torsion. It is known that the problem of torsion of a rod, in which free plane shift of its sections is permitted, reduces to the Poisson equation. The exact solution of this equation for a laminate rod entails substantial difficulties, and it was obtained for some comparatively simple shapes and structures of sections only. The present work is an attempt to construct an approximate applied theory of free torsion of orthotropic laminate thin-walled rods with a section of arbitrary shape; this theory is based on the equations of the theory composite shells which takes into account transverse deformations averaged over the wall thickness and changes of the metric properties of the space, taken up by the shell, across its thickness.