*Article* **Modelling of Longitudinal Elastic Wave Propagation in a Steel Rod Using the Discrete Element Method**

**Magdalena Knak 1,\*, Michał Nitka 2, Erwin Wojtczak <sup>1</sup> and Magdalena Rucka <sup>1</sup>**


**Abstract:** The paper deals with the issue of modelling elastic wave propagation using the discrete element method (DEM). The case of a longitudinal wave in a rod with a circular cross-section was considered. A novel, complex algorithm consisting of the preparation of models and simulation of elastic waves was developed. A series of DEM models were prepared for simulations, differing in discretisation and material parameters. Additional calculations with the finite element method (FEM) were performed. Numerical wave signals were obtained from each simulation and compared with experimental results to choose the best DEM model based on the correlation between the waveforms. Moreover, dispersion curves were prepared for each model to verify the agreement with the Pochhammer-Chree wave propagation theory. Both experimental and theoretical approaches indicated the same model as the most suitable. The analysis results allowed stating that DEM can be successfully used for modelling wave propagation in structural rods.

**Keywords:** guided waves; longitudinal wave; discrete element method; finite element method; numerical modelling; dispersion curves
