Application of Modal Analysis for Evaluation of the Impact Resistance of Aerospace Sandwich Materials

Abstract

Impact resistance of different types of composite sandwich beams is evaluated by studying vibration response changes (natural frequency and damping ratio). This experimental works will help aerospace structural engineer in assess structural integrity using classification of impact resistance of various composite sandwich beams (entangled carbon and glass fibers, honeycomb and foam cores). Low velocity impacts are done below the BVID limit in order to detect damage by vibration testing that is hardly visible on the surface. Experimental tests are done using both burst random and sine dwell testing in order to have a better confidence level on the extracted modal parameters. Results show that the entangled sandwich beams have a better resistance against impact as compared to classical core materials.

Evaluation of the survivability of CFRP honeycomb-cored panels in compression after impact tests

“…The hot topic of experimental mechanics is to obtain new experimental data on the processes of deformation and destruction of layered-fiber polymeric composite materials in the presence of operational stress concentrators. A large number of scientific papers [1][2][3][4][5][6][7] are devoted to the study of the residual strength degradation of composite sandwich plates under various environmental conditions. The paper describes the methods and progress of testing, the findings in the form of dependencies of the residual strength (maximum compressive load after impact) at the same level of impact (impact energy).…”