Damage identification of prepreg composites subject to accelerated fatigue tests

Abstract

The fatigue behavior of composite materials under time-dependent loading is investigated. Fatigue is induced in test beams using an electro-magnetic shaker. The test beams made of prepreg composite materials with a layup [(±45)2]S before and after fatigue loading are used as a case study for the proposed method. The averaged stiffness properties of the test specimen are monitored during the fatigue cycles by measuring the first natural frequency. The first bending mode shapes of the test beams are measured using a laser scanning vibrometer at selected fatigue stages. Based on this modal information, the (reduced) bending stiffness distribution of the test beam is identified using an inverse method