Damage mechanics of composites under fatigue loads

René Rieser

Research output: ThesisMaster's Thesis

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Abstract

This study investigates the fatigue behaviour of glass fibre reinforced polymer (GFRP) laminates. Unidirectional layups (UD), biaxial layups from ±15° to ±75° in 15° steps and a 0° dominated multiaxial layup were manufactured. Specimens were produced with the vacuum pressing technology. Damage evolution was observed in detail during the cyclic tension-tension fatigue test. It was linked to the decreasing cycle-dependent linear-elastic properties. Damage initiation and growth until specimen failure were observed using a camera system and transmitted light. It was found, that some layups do not develop a characteristic damage state (CDS) because delaminations evolved before crack accumulation in the entire specimen. The applied stresses in the fatigue tests were calculated with the classical laminate theory (CLT) and Puck’s failure criterion for static loads. It was used to show the unsuitability of a static approach under cyclic loads. Non-destructive testing (NDT) methods were evaluated for their applicability to damage monitoring during fatigue tests.
Translated title of the contributionSchädigungsmechanik von faserverstärkten Kunststoffen unter Ermüdungsbeanspruchungen
Original languageEnglish
QualificationDipl.-Ing.
Supervisors/Advisors
  • Stelzer, Steffen, Co-Supervisor (internal)
  • Pinter, Gerald Gerhard, Supervisor (internal)
Award date1 Jul 2016
Publication statusPublished - 2016

Bibliographical note

embargoed until null

Keywords

  • damage mechanics
  • fatigue
  • NDT
  • non-destructive testing
  • damage evolution

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