Spectral Domain Force Identification of Impulsive Loading in Beam Structures

In this paper, an identification method is presented for calculating impulsive loads from the propagating mechanical wave which are produced in beam-like structures. This method uses a spectral finite element method (SFEM) model of a segment of the structure to calculate force information from the measured response. The SFEM model is prepared from the Euler-Bernoulli beam equation in the frequency domain. The method is studied using simulated response data and then applied to data collected from an experimental system. Excellent performance is observed for nominal conditions and a parametric study is performed to determine how different factors affect accuracy. Factors studied include structure size, loading location, and loading duration. When limited to only acceleration data, the use of finite differencing methods to obtain the required slope response information is determined to provide the most significant source of error in the identified force information.