Abstract
A new concept, the equivalent inherent strain g^eq_θ, is proposed for the measurement of axisymmetric residual stresses, based on the inherent strain theory. That is combining the radial and tangential inherent strain components gr, gθ into one parameter g^eq_θ in computing the axially uniform axisymmetric residual stresses. Based on this concept, the difficulty of estimating the value of gr is overcome and stress distribution in a long cylinder can be computed by merely estimating g^eq_θ and axial inherent strain component gz from measured strains in tangential and axial directions. Stress distribution in a thin disk or ring can be simply obtained by estimating g^eq_θ from measured strain in tangential direction. The concept was verified by the experiment of measuring residual stresses in a pipe with cladding. A numerical simulation was carried out to demonstrate that the measuring method based on g^eq_θ has both the convenience of the Sachs method and the high accuracy of the inherent strain method.
