Impacted beam is popularly confronted at many engineering problems. Many studies on this subject have been published, most of which are focused on either the calculation of the response or the prediction of the impact forces. When the impulse response function is known, both the response and force analyses can be executed by the convolution and the deconvolution approach. Noting that the impact occurs within a very short period, in the order of micro-seconds, it takes time when the impacted beam is deflected at a certain point apart from the impacted point. Therefore, the conventional mode superposition method is not good to analyze the impact phenomenon exactly at the very early instant of impact; the wave propagation technique can give more accurate results.
The impulse response functions (force-strain relations) for Euler-Bernoulli and Timoshenko beams are considered. The response of a beam to a transverse impact force, including reflection at the boundary, is numerically obtained with the convolution approach using the impulse response function obtained by Laplace transform. Using this relation, the impact force history is determined in the time domain and results are compared with those from Hertz's contact law. In the case of an arbitrary point impact, the location of the impact force and its time-history can be simultaneously found. The parameters of impact force model are identified using the recovered force and compared with the Hertz's contact model. In order to verify the proposed algorithm, measurements were done using an impact hammer and a steel ball drop test and these results are also compared with the simulated values.
