PSI - Issue 28

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2019) 000–000

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 28 (2020) 1709–1718

© 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo Abstract In this work, damage delamination or plies separation was analyzed and monitored during fatigue tests on two different series of CFRP specimens. The research work includes two cases of work, the first is delamination initiation due to bending loads on cross section CFRP samples and the second one deals with delamination due to wrinkle defect presence. Preliminary static tests are carried out with aid of digital image correlation technique to evaluate failure static loads and strains field modifications. Fatigue experimental tests were performed with non-destructive thermographic, optical and ultrasonic monitoring. This study includes an analysis of the damage to rupture behavior of the material through the mechanical tensile test and a non-destructive inspection procedure is adopted during HCF load, in order to detect in real time local compliance variations and damage initiation. Thermographic continuous monitoring and occasional ultrasonic analysis are implemented with the purpose to analyze composite anomalies during fatigue life and elaborate a method for the identification of the wrinkle induced failure well before rupture. Thermal and ultrasonic data are processed with MATLAB codes for damage evaluation with compliance data acquired during tests. © 2020 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo Keywords: CFRP; delamination; digital image correlation; fatigue; thermography; ultrasonic technique; wrinkle. 1. Introduction Non-destructive (ND) detection and material defect characterization represent the main useful procedure for prediction of mechanical decay caused by local composite interlaminar damage of mechanical structures (David-West B 1st Virtual European Conference on Fracture Thermal and ultrasonic analysis of fatigue damaged CFRP samples under traction and bending load F. W. Panella a and A. Pirinu a * a University of Salento, Department of Innovation Engineering, Lecce 73100, Italy

* Corresponding author. Tel.: +39 (0)832 297786; fax: +39 (0)832 297768. E-mail address: alessandra.pirinu@unisalento.it

2452-3216 © 2020 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo

2452-3216 © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo 10.1016/j.prostr.2020.10.146