Abstract
A numerical deconvolution method is presented which, by accounting for the specimen geometry and the experimental deformation mode imposed, allows conversion of measured internal-friction (MIF) data into amplitude-dependent intrinsic internal-friction (IIF) values. The only requirement of the procedure is the assumption usually made that the IIF can be unequivocally described using some properly chosen scalar strain parameter. The method, which consists of adjusting an implicit empirical function to the experimental values, is implemented here to treat the case of parallelepiped specimens of arbitrary width-to-thickness ratio deforming in torsion. The method is tested by applying it to actual data of MIF obtained from torsion experiments performed on circular and rectangular beams of the same material. The agreement between the IIF against strain curves that result after deconvoluting the MIF curves associated with the different specimen geometries supports the validity of the method.