In this study we developed an experimental method to identify the impact force on a reinforced concrete slab. A transfer function obtained experimentally between the acceleration response and the force history applied to a point of the structure was used. To regularise the solution obtained with this inverse problem, we used the Tikhonov method. To locate the impact force, we used an experimental method based on the minimisation of an objective function created from the transfer functions between several impact locations, forming a mesh structure, and several measuring points. Characterising the impact means locating the impactor and identifying the load. Meanwhile, a numerical model is developed using Abaqus to characterise impact force, and allow access to the state constraints and damage level.