Validation of a Wheelset Finite Element Model for Static Structural Analysis and Inverse Force Identification

This paper focus on the validation of the strain measurement chain of an instrumented wheelset Finite Element (FE) static model for railway applications equipped with strain gauges, involving the inverse measurement of contact forces exchanged at the wheel-rail interface. Previous activities have highlighted some concerns about the static response of the FE model, obtained with a commercial FE software, which gave rise to the necessity of validating and assessing its static performances and reliability with a specific simulation. The chosen case study reproduces a test known as the “deformation test”, in which the strain state of a surface is evaluated at various points to reconstruct the punctual trend of deformations. The FE model is compared with reference experimental results obtained through a static calibration bench for railway axles. Considering the uncertainty in the actual measurement chain, a good agreement is achieved between experimental measurements and synthetic data with an average relative error of 5%. For further validation, the inverse force identification and the selection of radii with greater sensitivity to forces and low relative error with experimental data, is also presented based on strain gauge coefficients of influence, obtained solving the inverse system of strain equations with linear superposition technique and Moore-Penrose pseudo inverse of the load matrix.