Approximation of structural intensity from experimental structural response data using a hybrid method − methodology, verification, and validation

Structural intensity is a response quantity that allows visualization and quantification of the vibrational power flow in structures. Numerical simulations allow for easy calculation, i.e., by combining standard result datasets of finite element analysis. However, this is not the case for experimental data, where usually an incomplete set of response quantities (i.e., just translational responses) of a subset of the degrees of freedom of the corresponding finite element model serves as the fundamental dataset to compute the structural intensity. This paper provides a comprehensive guide for a hybrid method that allows the calculation of structural intensity on arbitrary surfaces in three-dimensional space. The hybrid method utilizes experimentally acquired structural response data as an input. The corresponding measurement point locations build a mesh with associated trial functions. Furthermore, we verify the methodology utilizing numerical data to quantify the method's accuracy. Moreover, comparing structural intensity fields acquired from a numerical model and measurement data helps to validate the proposed approach further. Finally, the methodology supports engineers in utilizing the concept of structural intensity to optimize mechanical systems in terms of structural dynamics, e.g., the smart application of damping elements to control system dynamics efficiently.