An improved method for the reconstruction of a distributed force acting on a vibrating structure

Indirectly reconstructing distributed forces from measured structural response is necessary when the direct measurement of these dynamic forces is not possible. An improved method for reconstructing distributed forces is developed in this paper. Unlike the traditional modal method for force reconstruction, the forcing spatial function is decomposed only over the known forcing region. Numerical simulations illustrate that when compared with the traditional modal method, this new method tends to obtain better reconstruction results while requiring fewer basis functions. A theoretical proof is provided to reveal the applicability and limitations of this new method. It turns out that this approach, like other inverse methods, can also be an ill-posed method. To address this issue, a regularization process is introduced to increase the inverse stability. Numerical results show that when the regularization process is applied to simulated response measurements that include noise, the new method is able to reconstruct spatially distributed external forces with improved accuracy.