Schuhmacher, Andreas3; Hald, Jørgen4; Rasmussen, Karsten Bo3; Hansen, Per Christian5
1 Scientific Computing, Department of Informatics and Mathematical Modeling, Technical University of Denmark2 Department of Informatics and Mathematical Modeling, Technical University of Denmark3 Department of Acoustic Technology, Technical University of Denmark4 unknown5 Department of Applied Mathematics and Computer Science, Technical University of Denmark
Whereas standard boundary element calculations focus on the forward problem of computing the radiated acoustic field from a vibrating structure, the aim of the present work is to reverse the process, i.e., to determine vibration from acoustic field data. This inverse problem is brought on a form suited for solution by means of an inverse boundary element method. Since the numerical treatment of the inverse source reconstruction results in a discrete ill-posed problem, regularisation is imposed to avoid unstable solutions dominated by errors. In the present work the emphasis is on Tikhonov regularisation and parameter-choice methods not requiring an error norm estimate for choosing the right amount of regularisation. We demonstrate that the L-curve criterion is robust with respect to the errors in real measurement situations.