The aim of the present study was to introduce a new algorithm for reconstructing the eigenstrain fields in engineering components. A 2D discrete inverse eigenstrain study of residual stresses was carried out on a worn railhead sample. Its residual elastic strain distribution was obtained by neutron diffraction measurement in Stress-Spec, FRMII and used as the input for eigenstrain reconstruction. A new eigenstrain base function-tent was introduced to capture the fully two-dimensional variation of eigenstrain distribution. An automated sequential tent generation scheme was programed in ABAQUS ™ with its preprocessor to load the experimental data and postprocessor to carry out the optimization to obtain the eigenstrain coefficients. The reconstructed eigenstrain field incurs residual stress distribution in the railhead simulation, which showed good agreement with the experimental data.