Estimating degradation of strength of neat PEEK and PEEK-CF laminates under cyclic loading by mechanical hysteresis loops

Abstract

A method for assessing the degradation of mechanical properties of neat polyetheretherketone and its laminated composite reinforced with unidirectional carbon fibers is proposed. It is based on the calculation of the maximum and minimum strains in a cycle, as well as both dynamic and secant moduli estimated from mechanical hysteresis loops. These parameters reflect the material damage degree, enabling to predict its current mechanical state.

Prediction of Fatigue Life of Polyetherimide/Carbon Fiber Particulate Composites at Various Maximum Stresses and Filler Contents

“…The fatigue properties of the PCMs were assessed by calculating the parameters of the mechanical hysteresis loops drawn in the strain–stress coordinates [ 35 ]. Stresses were calculated using the data recorded with a load cell of a testing machine.…”