Numerical modelling of drop mass shape influence on energy absorption of welded wire mesh in dynamic impact conditions

Underground mines rely on a ground support system (i.e. reinforcement and surface support elements such as welded wire mesh) to control rock deformation and maintain excavation stability under dynamic loading conditions. Designing an effective ground support system requires a detailed understanding of the mechanical behaviour of these support components and their response to impact scenarios. This study investigates the influence of drop mass geometry on the deformation and failure mechanisms of welded wire mesh utilising a 3D finite element analysis (FEA) based on geometries used in laboratory testing. Five drop mass configurations, prism, spherical, cylindrical, ETAG 027, and irregular, were evaluated under the same energy input to explore their effects on mesh behaviour. Although the developed dynamic testing setup offers valuable insights into mesh performance, the lack of standardised drop mass shapes remains a significant challenge, as it causes inconsistencies in test results and complicates data comparison across different studies or reliable experiment replication. The FEA model was developed and calibrated using experimental data. The results demonstrated that the drop mass shape strongly affects load distribution, displacement patterns and the extent of damage in the mesh. The prism shape, used for calibration, provided a good match with the laboratory result. Cylindrical geometries demonstrated more favourable energy dissipation, absorbing 5.69 kJ, whereas the irregular and spherical shapes exhibited lower energy absorption, 2.83 kJ and 2.55 kJ, respectively, due to the concentrated nature of the initial impact load being distributed over a smaller contact area. The ETAG 027 geometry produced a balanced response, with a peak displacement of approximately 152.77 mm and an energy absorption of 3.06 kJ, accompanied by moderately distributed plastic deformation. This study can support the development of more reliable testing procedures and energy-based design approaches for support systems in dynamic underground environments.