Practical Considerations for Estimating Road Vehicle Frequency Response Functions from Response Data

This paper describes the application of a practical method to estimate the dynamic characteristics (frequency response function) of road vehicles using only on-the-road vertical vibration response data measured during nominally constant operating speeds. While several methods exist to estimate these dynamic characteristics, they are generally either inexact or prohibitively resource intensive. A review of two analytical approaches for estimating the frequency response function of road vehicles using only on-the-road vibration response data is presented. The first approach is based on the assumption that the road elevation profile takes the form of a specified spectral function. The second approach is based on the random decrement technique. A practical, step-by-step guide to undertaking on-the-road vehicle vibration measurements is included and provides numerous useful tips and considerations that should be taken into account. An investigation was also undertaken into the minimum record length (i.e. fraction of road length) required to accurately estimate the dynamic characteristics of road vehicles using a Monte Carlo simulation. From the study, it was found that a minimum road length of 10 - 15 km is sufficient to obtain a reasonably accurate estimate. Copyright (C) 2017 John Wiley & Sons, Ltd.