During aerospace missions, payloads and subsystems endure extreme dynamic loads. Pyrotechnic devices, such as those used for stage separation, secondary structure deployment, or appendage release, produce high-energy transients known as pyroshocks. These pyroshocks pose a significant threat to electronic components and can compromise the success of the mission. Qualifying hardware therefore demands pyroshock testing, typically performed by striking resonant plates with projectiles or hammers to reproduce the shock response spectrum prescribed in standards. Because these tests rely on iterative, empirical tuning, experimental qualification remains time consuming and cost intensive. State of the art numerical methods can shorten this process by predicting the responses of resonant plates, but their accuracy hinges on correctly modelling impact forces and contact durations, which govern the resulting spectral content.