15 Abr Doctoral thesis on notched strength and size effect in pseudo-ductile composite laminates
On April 11, 2024, Anbazhagan Subramani defended his PhD thesis entitled “Notched strength and size
effect in pseudo-ductile composite laminates” supervised by Dr. Pere Maimi and Dr. Josep Costa
Balanzat from AMADE – University of Girona.
This PhD research systematically investigates the influence of pseudo-ductility on size-effect behaviour
(reduction of notched strength with increasing specimen size) in composites. While size-effect in FRPs is
known, experimental evidence on pseudo-ductile laminates has been limited to single-notch sizes.
Using finite element modelling, the study uncovered the relationships between pseudo-ductile material
parameters and notched strength. Building on this, design tools were created (based on modifications to
Bazant’s universal size effect laws) to characterise the notched strength of any bi-linear pseudo-ductile
material. These concepts have broad applicability, as demonstrated with plastic hardening materials
containing cracks.
The experimental work employed innovative techniques to characterise the strain non-linearities,
pseudo-ductile strain, and pseudo-ductile damage derived from DIC images of open-hole pseudo-ductile
specimens (single notch radius).
Anbazhagan Subramani would like to acknowledge the support of Spanish Ministerio de Ciencia,
Innovacion y Universidades through the projects TOUGHCOMP (RTI2018-097880-B-I00) and SUBHYCO
(PID2021-126989OB-I00) and the Mobility grant (MOB-21) from Universitat de Girona. Anbazhagan
Subramani would also like to acknowledge the support of Dr. Joel Cugnoni from Haute Ecole d’Ingénierie
et de Gestion du Canton de Vaud for the experiments.
