Numerical and Experimental Extraction of Dynamic Parameters for Pyramidal Truss Core Sandwich Beams with Laminated Face Sheets

Sandwich beams that are composed of laminated face sheets and aluminum pyramidal truss cores are considered to be essential elements of building and aerospace structures. In this paper, a methodology for the experimental and numerical analysis of such structures is presented in order to support their industrial application. The scope of the present research covers both the experimental and numerical extraction of the dynamic parameters of the sandwich beams. Vibration tests are performed while using an optical system for three-dimensional vibrations sensing. The in-plane and out-of-plane vibration modes can thus be examined. A detailed numerical model of the sandwich beam is developed, including an adhesive joint (an additional layer of material) between the parent components of the beam. The numerically predicted modal parameters (eigenfrequencies, mode shapes, modal loss factors) are comported with their corresponding experimentally-obtained values. The modal loss factors are predicted based on the strain energy method, for which a brief theoretical introduction is provided. The obtained experimental and numerical results coincide with good accuracy. The circumstances for possible model simplifications are provided depending on the solution objectives.