Uncertainty Quantification in Experimental Structural Dynamics Identification of Composite Material Structures

Abstract

Aerospace and wind energy structures are extensively using components made of composite materials. Since these structures are subjected to dynamic environments with time-varying loading conditions, it is important to model their dynamic behavior and validate these models by means of vibration experiments. Modal testing results depend on numerous factors introducing uncertainty to the measurement results. Different experimental techniques applied to the same test item or testing numerous nominally identical specimens yields different test results. This paper presents a systematic approach for uncertainty evaluation in experimentally estimated models. Investigated structures are plates, fuselage panels and helicopter main rotor blades as they represent different complexity levels ranging from coupon, through sub-component up to fully assembled structures made of composite materials. To evaluate the variability of the identified parameters, a statistical method is implemented for processing an extensive collection of experimental data.