The University of Sheffield
3 files - A Python algorithm for phase angle and amplitude correction of pressure bar signals

posted on 2023-11-20, 17:10 authored by Arthur Van LerbergheArthur Van Lerberghe, Andrew BarrAndrew Barr


When processing signals from split-Hopkinson pressure bar (SHPB) experiments, it is frequently presumed that longitudinal stress waves in the pressure bars travel one-dimensionally at a common velocity of c0. Hence, measurements recorded at the strain gauges are commonly simply translated to the end of the bar using a suitable time delay. In reality, stress waves travel at a certain phase velocity, cp, which varies with frequency, bar diameter, one-dimensional wave speed and Poisson’s ratio. As the frequency of a wave rises, the phase velocity drops, resulting in signal dispersion as it propagates down the bar. The dispersion of the stress pulse is followed by a frequency-dependent fluctuation in stress and strain throughout the bar cross-section. Therefore, a signal recorded on the surface of the bar at some distance from the specimen will not accurately represent the stresses the specimen was subjected to, and hence cannot be used to objectively measure the specimen response.


  • A Python function, with the documentation on the use of the function included in the file as comments. It requires to run.
  • A Python function, with the documentation on the use of the function included in the file as comments. It requires the folder dispersion_factors.
  • 'dispersion_factors' zip folder: A folder containing pre-calculated values of normalised frequency, normalised velocity and factors m1 and m2 for a material with a Poisson's ratio of 0.29 (i.e. stainless steel). This was calculated using the algorithm (Van Lerberghe, A., Barr, A. D. (2023)), available on GitHub and ORDA, see links below.


  • Tyas, A., Pope, D.J., (2005). Full correction of first-mode Pochhammer–Chree dispersion effects in experimental pressure bar signals. Measurement science and technology, 16(3), p.642.




Arthur Van Lerberghe & Andrew D. Barr






  • There is no personal data or any that requires ethical approval


  • The data complies with the institution and funders' policies on access and sharing

Sharing and access restrictions

  • The data can be shared openly

Data description

  • The file formats are open or commonly used

Methodology, headings and units

  • Headings and units are explained in the files