On the use of the Combined Loading Compression fixture to estimate the intralaminar compressive fracture toughness of composites

• Type: Article in International Scientific Journal
• Date: 2023

Authors

Dalli, D (Author) Other; Danzi, F (Author) Other; Campos, PJS (Author) Other; Arteiro, A (Author) FEUP; Camanho, PP (Author) Other

Journal

Title: Engineering Fracture Mechanics

Vol. 289

ISSN: 0013-7944

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 0 Citations

Scopus - 1 Citation

Other information

Authenticus ID: P-00Y-SAM

DOI: 10.1016/j.engfracmech.2023.109444

Abstract (EN): This study reassesses the constraint effect provided by a Combined Loading Compression (CLC) fixture on notched specimens used to measure the compressive intralaminar fracture toughness of composite materials. An experimental campaign is carried out to determine whether a variation in the specimen gauge section length would result in a significant change in the nominal strength of Double Edge Notch CLC specimens. Following the testing of six sets of different specimen geometries for both a uni-directional thermoplastic and a bi-directional woven thermoset com-posite, the effect of the gauge length is analysed using the size-effect method. Results show that nominal notched strength variation is minimal, suggesting that the CLC clamp does not effectively constrain the gripped sections against in-plane deformations. This assessment proves that the correction factor used in the determination of the R-curve needs to be computed considering the entire specimen geometry, including the gripped regions. Furthermore, the results reveal that previous characterisation campaigns conducted using end-loaded Double Edge Notch Compres-sion specimens could have led to a significant underestimation of the steady-state fracture toughness.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 11