Identification of wheel-rail contact forces based on strain measurement and finite element model of the rolling wheel

In railway mechanics, the wheel-rail contact force is an important measure in the analysis of different kinds of rolling contactfatigue as well as being used for track condition monitoring. As the contact force cannot be measured directly in the field, oneapproach is to measure the strain at certain points on an instrumented wheel and upon employing signal processing techniques,extract an estimation of the contact force. However, the obtained force is restricted in terms of frequency content, i.e. the resultsare not accurate close to certain resonance frequencies of the wheel, [2]. In order to investigate and overcome the experiencedproblems, a 3-D Finite Element model of the wheel is used in an inverse identification procedure [7], whereby the proper dynamicsof the system is taken into account. The method of signal processing using two Wheatstone bridges is compared withthe inverse identification scheme by means of synthetic data