On the determination of effective stiffness properties of multilayered axisymmetric beams via analytic and experimental approaches

In this work we derive formulas to compute effective torsion, extension, bending and shear stiffness coefficients for n-layered axisymmetric beams that take into account the coupling due to deformation between layers. Further, the contributions of this coupling are studied for the case of two- and three-layered circular cross-sections. Finally, we proceed to check the applicability of the results to a particular case of interest, that of unloaded endoscope shafts. For this purpose, we show the results of an experimental campaign carried out on the medical devices.